Hand-held postcard printer

ABSTRACT

A digital camera comprises an image sensor device for sensing an image. A processor processes the sensed image. A pagewidth printhead prints the sensed image. An ink supply arrangement supplies ink to the print head and the image is printed on print media from a supply of print media. The supply of print media is pre-marked with tokens designating that postage has been paid so that each image printed out on the print media has one such token associated with it.

CROSS REFERENCE TO RELATED APPLICATION

[0001] The present application is a divisional of and claims the benefitof U.S. application Ser. No. 09/113,086 filed on Jul. 10, 1998, theentire contents of which are herein incorporated by reference.

FIELD OF THE INVENTION

[0002] The present invention relates substantially to the concept of adisposable camera having instant printing capabilities and inparticular, discloses a method integrating the electronic components ofa camera system.

BACKGROUND OF THE INVENTION

[0003] Recently, the concept of a “single use” disposable camera hasbecome an increasingly popular consumer item. Disposable camera systemspresently on the market normally include an internal film roll and asimplified gearing mechanism for traversing the film roll across animaging system including a shutter and lensing system. The user, afterutilizing a single film roll returns the camera system to a filmdevelopment center for processing. The film roll is taken out of thecamera system and processed and the prints returned to the user. Thecamera system is then able to be re-manufactured through the insertionof a new film roll into the camera system, the replacement of any wornor wearable parts and the re-packaging of the camera system inaccordance with requirements. In this way, the concept of a single use“disposable” camera is provided to the consumer.

[0004] Recently, a camera system has been proposed by the presentapplicant which provides for a handheld camera device having an internalprint head, image sensor and processing means such that images sense bythe image sensing means, are processed by the processing means andadapted to be instantly printed out by the printing means on demand. Theproposed camera system further discloses a system of internal “printrolls” carrying print media such as film on to which images are to beprinted in addition to ink for supplying to the printing means for theprinting process. The print roll is further disclosed to be detachableand replaceable within the camera system.

[0005] Unfortunately, such a system is likely to only be constructed ata substantial cost and it would be desirable to provide for a moreinexpensive form of instant camera system which maintains a substantialnumber of the quality aspects of the aforementioned arrangement.

[0006] It would be further advantageous to provide for the effectiveinterconnection of the sub components of a camera system.

SUMMARY OF THE INVENTION

[0007] According to the invention, there is provided a recyclable,one-time use, print on demand, digital camera comprising:

[0008] an image sensor device for sensing an image;

[0009] a processing means for processing said sensed image;

[0010] a pagewidth print head for printing said sensed image;

[0011] an ink supply means for supplying ink to the print head; and

[0012] a supply of print media on to which said image is printed, thesupply of print media being pre-marked with tokens designating thatpostage has been paid so that each image printed out on the print mediahas one such token associated with it.

[0013] Preferably, the supply of print media is in the form of a roll,the tokens being pre-printed at regularly spaced intervals on onesurface of the print media.

[0014] Each token may have an address zone and a blank zone for writingassociated with it on said one surface to provide a postcard effect.

[0015] Each image may be printed on an opposed surface of the printmedia.

[0016] The token may be in the form of a postage stamp which is in acurrency of a country in which the camera is bought, with a notice tothat effect being carried on an exterior of that camera. Preferably, thecamera has a sleeve placed about a casing of the camera. The notice maythen be carried on the sleeve of the camera.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Not with standing any other forms which may fall within the scopeof the present invention, preferred forms of the invention will now bedescribed, by way of example only, with reference to the accompanyingdrawings in which:

[0018]FIG. 1 illustrates a front perspective view of the assembledcamera of the preferred embodiment;

[0019]FIG. 2 illustrates a rear perspective view, partly exploded, ofthe preferred embodiment;

[0020]FIG. 3 is a perspective view of the chassis of the preferredembodiment;

[0021]FIG. 4 is a perspective view of the chassis illustrating mountingof electric motors;

[0022]FIG. 5 is an exploded perspective view of the ink supply mechanismof the preferred embodiment;

[0023]FIG. 6 is a rear perspective view of the assembled form of the inksupply mechanism of the preferred embodiment;

[0024]FIG. 7 is a front perspective view of the assembled form of theink supply mechanism of the preferred embodiment;

[0025]FIG. 8 is an exploded perspective view of the platten unit of thepreferred embodiment;

[0026]FIG. 9 is a perspective view of the assembled form of the plattenunit;

[0027]FIG. 10 is also a perspective view of the assembled form of theplatten unit;

[0028]FIG. 11 is an exploded perspective view of the printhead recappingmechanism of the preferred embodiment;

[0029]FIG. 12 is a close up, exploded perspective view of the recappingmechanism of the preferred embodiment;

[0030]FIG. 13 is an exploded perspective view of the ink supplycartridge of the preferred embodiment;

[0031]FIG. 14 is a close up, perspective view, partly in section, of theinternal portions of the ink supply cartridge in an assembled form;

[0032]FIG. 15 is a schematic block diagram of one form of chip layer ofthe image capture and processing chip of the preferred embodiment;

[0033]FIG. 16 is an exploded perspective view illustrating the assemblyprocess of the preferred embodiment;

[0034]FIG. 17 illustrates a front exploded perspective view of theassembly process of the preferred embodiment;

[0035]FIG. 18 illustrates a perspective view of the assembly process ofthe preferred embodiment;

[0036]FIG. 19 illustrates a perspective view of the assembly process ofthe preferred embodiment;

[0037]FIG. 20 is a perspective view illustrating the insertion of theplatten unit in the preferred embodiment;

[0038]FIG. 21 illustrates the interconnection of the electricalcomponents of the preferred embodiment;

[0039]FIG. 22 illustrates the process of assembling the preferredembodiment; and

[0040]FIG. 23 is a perspective view further illustrating the assemblyprocess of the preferred embodiment.

DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS

[0041] Turning initially simultaneously to FIG. 1 and FIG. 2 there areillustrated perspective views of an assembled camera constructed inaccordance with the preferred embodiment with FIG. 1 showing a frontperspective view and FIG. 2 showing a rear perspective view. The camera1 includes a paper or plastic film jacket 2 which can include simplifiedinstructions 3 for the operation of the camera system 1. The camerasystem 1 includes a first “take” button 4 which is depressed to capturean image. The captured image is output via output slot 6. A further copyof the image can be obtained through depressing a second “printer copy”button 7 whilst an LED light 5 is illuminated. The camera system alsoprovides the usual viewfinder 8 in addition to a CCD imagecapture/lensing system 9.

[0042] The camera system 1 provides for a standard number of outputprints after which the camera system 1 ceases to function. A prints leftindicator slot 10 is provided to indicate the number of remainingprints. A refund scheme at the point of purchase is assumed to beoperational for the return of used camera systems for recycling.

[0043] Turning now to FIG. 3, the assembly of the camera system is basedaround an internal chassis 12 which can be a plastic injection moldedpart. A pair of paper pinch rollers 28, 29 utilized for de-curling aresnap fitted into corresponding frame holes eg. 26, 27.

[0044] As shown in FIG. 4, the chassis 12 includes a series of mutuallyopposed prongs e.g. 13, 14 into which is snapped fitted a series ofelectric motors 16, 17. The electric motors 16, 17 can be entirelystandard with the motor 16 being of a stepper motor type. The motors16,17 include cogs 19, 20 for driving a series of gear wheels. A firstset of gear wheels is provided for controlling a paper cutter mechanismand a second set is provided for controlling print roll movement.

[0045] Turning next to FIGS. 5 to 7, there is illustrated an ink supplymechanism 40 utilized in the camera system. FIG. 5 illustrates a rearexploded perspective view, FIG. 6 illustrates a rear assembledperspective view and FIG. 7 illustrates a front assembled view. The inksupply mechanism 40 is based around an ink supply cartridge 42 whichcontains printer ink and a print head mechanism for printing outpictures on demand. The ink supply cartridge 42 includes a side aluminumstrip 43 which is provided as a shear strip to assist in cutting imagesfrom a paper roll.

[0046] A dial mechanism 44 is provided for indicating the number of“prints left”. The dial mechanism 44 is snap fitted through acorresponding mating portion 46 so as to be freely rotatable.

[0047] As shown in FIG. 6, the mechanism 40 includes a flexible PCBstrip 47 which interconnects with the print head and provides forcontrol of the print head. The interconnection between the Flex PCBstrip and an image sensor and print head chip can be via Tape AutomatedBonding (TAB) strips 51, 58. A molded aspherical lens and aperture shim50 (FIG. 5) is also provided for imaging an image onto the surface ofthe image sensor chip normally located within cavity 53 and a light boxmodule or hood 52 is provided for snap fitting over the cavity 53 so asto provide for proper light control. A series of decoupling capacitorse.g. 34 can also be provided. Further a plug 45 (FIG. 7) is provided forre-plugging ink holes after refilling. A series of guide prongs e.g.55-57 are further provided for guiding the flexible PCB strip 47.

[0048] The ink supply mechanism 40 interacts with a platten unit 60which guides print media under a printhead located in the ink supplymechanism. FIG. 8 shows an exploded view of the platten unit 60, whileFIGS. 9 and 10 show assembled views of the platten unit. The plattenunit 60 includes a first pinch roller 61 which is snap fitted to oneside of a platten base 62. Attached to a second side of the platten base62 is a cutting mechanism 63 which traverses the platen unit 60 by meansof a rod 64 having a screw thread which is rotated by means of coggedwheel 65 which is also fitted to the platten base 62. The screw threadedrod 64 mounts a block 67 which includes a cutting wheel 68 fastened viaa fastener 69. Also mounted to the block 67 is a counter actuator whichincludes a pawl. The pawl 71 acts to rotate the dial mechanism 44 ofFIG. 6 upon the return traversal of the cutting wheel. As shownpreviously in FIG. 6, the dial mechanism 44 includes a cogged surfacewhich interacts with pawl 71 thereby maintaining a count of the numberof photographs by means of numbers embossed on the surface of dialmechanism 44. The cutting mechanism 63 is inserted into the platten base62 by means of a snap fit via clips e.g. 74.

[0049] The platen unit 60 includes an internal recapping mechanism 80for recapping the printhead when not in use. The recapping mechanism 80includes a sponge portion 81 and is operated via a solenoid coil so asto provide for recapping of the print head. In the preferred embodiment,there is provided an inexpensive form of printhead re-capping mechanismprovided for incorporation into a handheld camera system so as toprovide for printhead re-capping of an inkjet printhead.

[0050]FIG. 11 illustrates an exploded view of the recapping mechanismwhilst FIG. 12 illustrates a close up of the end portion thereof There-capping mechanism 80 is structured around a solenoid including a 16turn coil 75 which can comprise insulated wire. The coil 75 is turnedaround a first stationery solenoid arm 76 which is mounted on a bottomsurface of the platen base 62 (FIG. 8) and includes a post portion 77 tomagnify effectiveness of operation. The arm 76 can comprise a ferrousmaterial.

[0051] A second moveable arm 78 of the solenoid actuator is alsoprovided. The arm 78 is moveable and is also made of ferrous material.Mounted on the arm is a sponge portion surrounded by an elastomer strip79. The elastomer strip 79 is of a generally arcuate cross-section andacts as a leaf spring against the surface of the printhead ink supplycartridge 42 (FIG. 5) so as to provide for a seal against the surface ofthe printhead ink supply cartridge 42. In the quiescent position anelastomer spring unit 87, 88 acts to resiliently deform the elastomerseal 79 against the surface of the ink supply unit 42.

[0052] When it is desired to operate the printhead unit, upon theinsertion of paper, the solenoid coil 75 is activated so as to cause thearm 78 to move down to be adjacent to the end plate 76. The arm 78 isheld against end plate 76 while the printhead is printing by means of asmall “keeper current” in coil 75. Simulation results indicate that thekeeper current can be significantly less than the actuation current.Subsequently, after photo printing, the paper is guillotined by thecutting mechanism 63 of FIG. 8 acting against aluminum strip 43, andrewound so as to clear the area of the re-capping mechanism 80.Subsequently, the current is turned off and springs 87, 88 return thearm 78 so that the elastomer seal is again resting against the printheadink supply cartridge.

[0053] It can be seen that the preferred embodiment provides for asimple and inexpensive means of re-capping a printhead through theutilization of a solenoid type device having a long rectangular form.Further, the preferred embodiment utilizes minimal power in thatcurrents are only required whilst the device is operational andadditionally, only a low keeper current is required whilst the printheadis printing.

[0054] Turning next to FIGS. 13 and 14, FIG. 13 illustrates an explodedperspective of the ink supply cartridge 42 whilst FIG. 14 illustrates aclose up sectional view of a bottom of the ink supply cartridge with theprinthead unit in place. The ink supply cartridge 42 is based around apagewidth printhead 102 which comprises a long slither of silicon havinga series of holes etched on the back surface for the supply of ink to afront surface of the silicon wafer for subsequent ejection via a microelectromechanical system. The form of ejection can be many differentforms such as those set out in the tables below.

[0055] Of course, many other inkjet technologies, as referred to theattached tables below, can also be utilized when constructing aprinthead unit 102. The fundamental requirement of the ink supplycartridge 42 is the supply of ink to a series of color channels etchedthrough the back surface of the printhead 102. In the description of thepreferred embodiment, it is assumed that a three color printing processis to be utilized so as to provide full color picture output. Hence, theprint supply unit includes three ink supply reservoirs being a cyanreservoir 104, a magenta reservoir 105 and a yellow reservoir 106. Eachof these reservoirs is required to store ink and includes acorresponding sponge type material 107-109 which assists in stabilizingink within the corresponding ink channel and inhibiting the ink fromsloshing back and forth when the printhead is utilized in a handheldcamera system. The reservoirs 104, 105, 106 are formed through themating of first exterior plastic piece 110 and a second base piece 111.

[0056] At a first end 118 of the base piece 111 a series of air inlet113-115 are provided. Each air inlet leads to a corresponding windingchannel which is hydrophobically treated so as to act as an inkrepellent and therefore repel any ink that may flow along the air inletchannel. The air inlet channel further takes a convoluted path assistingin resisting any ink flow out of the chambers 104-106. An adhesive tapeportion 117 is provided for sealing the channels within end portion 118.

[0057] At the top end, there is included a series of refill holes (notshown) for refilling corresponding ink supply chambers 104, 105, 106. Aplug 121 is provided for sealing the refill holes.

[0058] Turning now to FIG. 14, there is illustrated a close upperspective view, partly in section through the ink supply cartridge 42of FIG. 13 when formed as a unit. The ink supply cartridge includes thethree color ink reservoirs 104, 105, 106 which supply ink to differentportions of the back surface of printhead 102 which includes a series ofapertures 128 defined therein for carriage of the ink to the frontsurface.

[0059] The ink supply cartridge 42 includes two guide walls 124, 125which separate the various ink chambers and are tapered into an endportion abutting the surface of the printhead 102. The guide walls 124,125 are further mechanically supported by block portions e.g. 126 whichare placed at regular intervals along the length of the ink supply unit.The block portions 126 have space at portions close to the back ofprinthead 102 for the flow of ink around the back surface thereof.

[0060] The ink supply unit is preferably formed from a multi-partplastic injection mold and the mold pieces e.g. 110, 111 (FIG. 13) snaptogether around the sponge pieces 107, 109. Subsequently, a syringe typedevice can be inserted in the ink refill holes and the ink reservoirsfilled with ink with the air flowing out of the air outlets 113-115.Subsequently, the adhesive tape portion 117 and plug 121 are attachedand the printhead tested for operation capabilities. Subsequently, theink supply cartridge 42 can be readily removed for refilling by means ofremoving the ink supply cartridge, performing a washing cycle, and thenutilizing the holes for the insertion of a refill syringe filled withink for refilling the ink chamber before returning the ink supplycartridge 42 to a camera.

[0061] Turning now to FIG. 15, there is shown an example layout of theImage Capture and Processing Chip (ICP) 48.

[0062] The Image Capture and Processing Chip 48 provides most of theelectronic functionality of the camera with the exception of the printhead chip. The chip 48 is a highly integrated system. It combines CMOSimage sensing, analog to digital conversion, digital image processing,DRAM storage, ROM, and miscellaneous control functions in a single chip.

[0063] The chip is estimated to be around 32 mm² using a leading edge0.18 micron CMOS/DRAM/APS process. The chip size and cost can scalesomewhat with Moore's law, but is dominated by a CMOS active pixelsensor array 201, so scaling is limited as the sensor pixels approachthe diffraction limit.

[0064] The ICP 48 includes CMOS logic, a CMOS image sensor, DRAM, andanalog circuitry. A very small amount of flash memory or othernon-volatile memory is also preferably included for protection againstreverse engineering.

[0065] Alternatively, the ICP can readily be divided into two chips: onefor the CMOS imaging array, and the other for the remaining circuitry.The cost of this two chip solution should not be significantly differentthan the single chip ICP, as the extra cost of packaging and bond-padarea is somewhat cancelled by the reduced total wafer area requiring thecolor filter fabrication steps.

[0066] The ICP preferably contains the following functions: Function 1.5megapixel image sensor Analog Signal Processors Image sensor columndecoders Image sensor row decoders Analogue to Digital Conversion (ADC)Column ADC's Auto exposure 12 Mbits of DRAM DRAM Address Generator Colorinterpolator Convolver Color ALU Halftone matrix ROM Digital halftoningPrint head interface 8 bit CPU core Program ROM Flash memory ScratchpadSRAM Parallel interface (8 bit) Motor drive transistors (5) Clock PLLJTAG test interface Test circuits Busses Bond pads

[0067] The CPU, DRAM, Image sensor, ROM, Flash memory, Parallelinterface, JTAG interface and ADC can be vendor supplied cores. The ICPis intended to run on 1.5V to minimize power consumption and allowconvenient operation from two AA type battery cells.

[0068]FIG. 15 illustrates a layout of the ICP 48. The ICP 48 isdominated by the imaging array 201, which consumes around 80% of thechip area. The imaging array is a CMOS 4 transistor active pixel designwith a resolution of 1,500×1,000. The array can be divided into theconventional configuration, with two green pixels, one red pixel, andone blue pixel in each pixel group. There are 750×500 pixel groups inthe imaging array.

[0069] The latest advances in the field of image sensing and CMOS imagesensing in particular can be found in the October, 1997 issue of IEEETransactions on Electron Devices and, in particular, pages 1689 to 1968.Further, a specific implementation similar to that disclosed in thepresent application is disclosed in Wong et al., “CMOS Active PixelImage Sensors Fabricated Using a 1.8V, 0.25 μm CMOS Technology”, IEDM1996, page 915

[0070] The imaging array uses a 4 transistor active pixel design of astandard configuration. To minimize chip area and therefore cost, theimage sensor pixels should be as small as feasible with the technologyavailable. With a four transistor cell, the typical pixel size scales as20 times the lithographic feature size. This allows a minimum pixel areaof around 3.6 μm×3.6 μm. However, the photosite must be substantiallyabove the diffraction limit of the lens. It is also advantageous to havea square photosite, to maximize the margin over the diffraction limit inboth horizontal and vertical directions. In this case, the photosite canbe specified as 2.5 μm×2.5 μm. The photosite can be a photogate, pinnedphotodiode, charge modulation device, or other sensor.

[0071] The four transistors are packed as an ‘L’ shape, rather than arectangular region, to allow both the pixel and the photosite to besquare. This reduces the transistor packing density slightly, increasingpixel size. However, the advantage in avoiding the diffraction limit isgreater than the small decrease in packing density.

[0072] The transistors also have a gate length which is longer than theminimum for the process technology. These have been increased from adrawn length of 0.18 micron to a drawn length of 0.36 micron. This is toimprove the transistor matching by making the variations in gate lengthrepresent a smaller proportion of the total gate length.

[0073] The extra gate length, and the ‘L’ shaped packing, mean that thetransistors use more area than the minimum for the technology. Normally,around 8 μm² would be required for rectangular packing. Preferably, 9.75μm² has been allowed for the transistors.

[0074] The total area for each pixel is 16 μm², resulting from a pixelsize of 4 μm×4 μm. With a resolution of 1,500×1,000, the area of theimaging array 101 is 6,000 μm×4,000 μm, or 24 mm².

[0075] The presence of a color image sensor on the chip affects theprocess required in two major ways:

[0076] The CMOS fabrication process should be optimised to minimize darkcurrent

[0077] Color filters are required. These can be fabricated using dyedphotosensitive polyimides, resulting in an added process complexity ofthree spin coatings, three photolithographic steps, three developmentsteps, and three hardbakes.

[0078] There are 15,000 analog signal processors (ASPs) 205, one foreach of the columns of the sensor. The ASPs amplify the signal, providea dark current reference, sample and hold the signal, and suppress thefixed pattern noise (FPN).

[0079] There are 375 analog to digital converters 206, one for each fourcolumns of the sensor array. These may be delta-sigma or successiveapproximation type ADC's. A row of low column ADC's are used to reducethe conversion speed required, and the amount of analog signaldegradation incurred before the signal is converted to digital. Thisalso eliminates the hot spot (affecting local dark current) and thesubstrate coupled noise that would occur if a single high speed ADC wasused. Each ADC also has two four bit DAC's which trim the offset andscale of the ADC to further reduce FPN variations between columns. TheseDAC's are controlled by data stored in flash memory during chip testing.

[0080] The column select logic 204 is a 1:1500 decoder which enables theappropriate digital output of the ADCs onto the output bus. As each ADCis shared by four columns, the least significant two bits of the rowselect control 4 input analog multiplexors.

[0081] A row decoder 207 is a 1:1000 decoder which enables theappropriate row of the active pixel sensor array. This selects which ofthe 1000 rows of the imaging array is connected to analog signalprocessors. As the rows are always accessed in sequence, the row selectlogic can be implemented as a shift register.

[0082] An auto exposure system 208 adjusts the reference voltage of theADC 205 in response to the maximum intensity sensed during the previousframe period. Data from the green pixels is passed through a digitalpeak detector. The peak value of the image frame period before capture(the reference frame) is provided to a digital to analogue converter(DAC), which generates the global reference voltage for the column ADCs.The peak detector is reset at the beginning of the reference frame. Theminimum and maximum values of the three RGB color components are alsocollected for color correction.

[0083] The second largest section of the chip is consumed by a DRAM 210used to hold the image. To store the 1,500×1,000 image from the sensorwithout compression, 1.5 Mbytes of DRAM 210 are required. This equals 12Mbits, or slightly less than 5% of a 256 Mbit DRAM. The DRAM technologyassumed is of the 256 Mbit generation implemented using 0.18 μm CMOS.

[0084] Using a standard 8F cell, the area taken by the memory array is3.11 mm². When row decoders, column sensors, redundancy, and otherfactors are taken into account, the DRAM requires around 4 mm².

[0085] This DRAM 210 can be mostly eliminated if analog storage of theimage signal can be accurately maintained in the CMOS imaging array forthe two seconds required to print the photo. However, digital storage ofthe image is preferable as it is maintained without degradation, isinsensitive to noise, and allows copies of the photo to be printedconsiderably later.

[0086] A DRAM address generator 211 provides the write and readaddresses to the DRAM 210. Under normal operation, the write address isdetermined by the order of the data read from the CMOS image sensor 201.This will typically be a simple raster format. However, the data can beread from the sensor 201 in any order, if matching write addresses tothe DRAM are generated. The read order from the DRAM 210 will normallysimply match the requirements of a color interpolator and the printhead. As the cyan, magenta, and yellow rows of the print head arenecessarily offset by a few pixels to allow space for nozzle actuators,the colors are not read from the DRAM simultaneously. However, there isplenty of time to read all of the data from the DRAM many times duringthe printing process. This capability is used to eliminate the need forFIFOs in the print head interface, thereby saving chip area. All threeRGB image components can be read from the DRAM each time color data isrequired. This allows a color space converter to provide a moresophisticated conversion than a simple linear RGB to CMY conversion.

[0087] Also, to allow two dimensional filtering of the image datawithout requiring line buffers, data is re-read from the DRAM array.

[0088] The address generator may also implement image effects in certainmodels of camera. For example, passport photos are generated by amanipulation of the read addresses to the DRAM. Also, image framingeffects (where the central image is reduced), image warps, andkaleidoscopic effects can all be generated by manipulating the readaddresses of the DRAM.

[0089] While the address generator 211 may be implemented withsubstantial complexity if effects are built into the standard chip, thechip area required for the address generator is small, as it consistsonly of address counters and a moderate amount of random logic.

[0090] A color interpolator 214 converts the interleaved pattern of red,2×green, and blue pixels into RGB pixels. It consists of three 8 bitadders and associated registers. The divisions are by either 2 (forgreen) or 4 (for red and blue) so they can be implemented as fixedshifts in the output connections of the adders.

[0091] A convolver 215 is provided as a sharpening filter which appliesa small convolution kernel (5×5) to the red, green, and blue planes ofthe image. The convolution kernel for the green plane is different fromthat of the red and blue planes, as green has twice as many samples. Thesharpening filter has five functions:

[0092] to improve the color interpolation from the linear interpolationprovided by the color interpolator, to a close approximation of a sincinterpolation;

[0093] to compensate for the image ‘softening’ which occurs duringdigitisation;

[0094] to adjust the image sharpness to match average consumerpreferences, which are typically for the image to be slightly sharperthan reality. As the single use camera is intended as a consumerproduct, and not a professional photographic products, the processingcan match the most popular settings, rather than the most accurate;

[0095] to suppress the sharpening of high frequency (individual pixel)noise. The function is similar to the ‘unsharp mask’ process; and

[0096] to antialias Image Warping.

[0097] These functions are all combined into a single convolutionmatrix. As the pixel rate is low (less than 1 Mpixel per second) thetotal number of multiplies required for the three color channels is 56million multiplies per second. This can be provided by a singlemultiplier. Fifty bytes of coefficient ROM are also required.

[0098] A color ALU 113 combines the functions of color compensation andcolor space conversion into the one matrix multiplication, which isapplied to every pixel of the frame. As with sharpening, the colorcorrection should match the most popular settings, rather than the mostaccurate.

[0099] A color compensation circuit of the color ALU providescompensation for the lighting of the photo. The vast majority ofphotographs are substantially improved by a simple color compensation,which independently normalizes the contrast and brightness of the threecolor components.

[0100] A color look-up table (CLUT) 212 is provided for each colorcomponent. These are three separate 256×8 SRAMs, requiring a total of6,144 bits. The CLUTs are used as part of the color correction process.They are also used for color special effects, such as stochasticallyselected “wild color” effects.

[0101] A color space conversion system of the color ALU converts fromthe RGB color space of the image sensor to the CMY color space of theprinter. The simplest conversion is a 1's complement of the RGB data.However, this simple conversion assumes perfect linearity of both colorspaces, and perfect dye spectra for both the color filters of the imagesensor, and the ink dyes. At the other extreme is a tri-linearinterpolation of a sampled three dimensional arbitrary transform table.This can effectively match any non-linearity or differences in eithercolor space. Such a system is usually necessary to obtain good colorspace conversion when the print engine is a color electrophotographic

[0102] However, since the non-linearity of a halftoned ink jet output isvery small, a simpler system can be used. A simple matrix multiply canprovide excellent results. This requires nine multiplies and sixadditions per contone pixel. However, since the contone pixel rate islow (less than 1 Mpixel/sec) these operations can share a singlemultiplier and adder. The multiplier and adder are used in a color ALUwhich is shared with the color compensation function.

[0103] Digital halftoning can be performed as a dispersed dot ordereddither using a stochastic optimized dither cell. A halftone matrix ROM216 is provided for storing dither cell coefficients. A dither cell sizeof 32=32 is adequate to ensure that the cell repeat cycle is notvisible. The three colors—cyan, magenta, and yellow—are all ditheredusing the same cell, to ensure maximum co-positioning of the ink dots.This minimizes ‘muddying’ of the mid-tones which results from bleed ofdyes from one dot to adjacent dots while still wet. The total ROM sizerequired is 1 KByte, as the one ROM is shared by the halftoning unitsfor each of the three colors.

[0104] The digital halftoning used is dispersed dot ordered dither withstochastic optimized dither matrix. While dithering does not produce animage quite as ‘sharp’ as error diffusion, it does produce a moreaccurate image with fewer artifacts. The image sharpening produced byerror diffusion is artificial, and less controllable and accurate than‘unsharp mask’ filtering performed in the contone domain. The high printresolution (1,600 dpi×1,600 dpi) results in excellent quality when usinga well formed stochastic dither matrix.

[0105] Digital halftoning is performed by a digital halftoning unit 217using a simple comparison between the contone information from the DRAM210 and the contents of the dither matrix 216. During the halftoneprocess, the resolution of the image is changed from the 250 dpi of thecaptured contone image to the 1,600 dpi of the printed image. Eachcontone pixel is converted to an average of 40.96 halftone dots.

[0106] The ICP incorporates a 16 bit microcontroller CPU core 219 to runthe miscellaneous camera functions, such as reading the buttons,controlling the motor and solenoids, setting up the hardware, andauthenticating the refill station. The processing power required by theCPU is very modest, and a wide variety of processor cores can be used.As the entire CPU program is run from a small ROM 220 programcompatibility between camera versions is not important, as no externalprograms are run. A 2 Mbit (256 Kbyte) program and data ROM 220 isincluded on chip. Most of this ROM space is allocated to data foroutline graphics and fonts for specialty cameras. The programrequirements are minor. The single most complex task is the encryptedauthentication of the refill station. The ROM requires a singletransistor per bit.

[0107] A Flash memory 221 may be used to store a 128 bit authenticationcode. This provides higher security than storage of the authenticationcode in ROM, as reverse engineering can be made essentially impossible.The Flash memory is completely covered by third level metal, making thedata impossible to extract using scanning probe microscopes or electronbeams. The authentication code is stored in the chip when manufactured.At least two other Flash bits are required for the authenticationprocess: a bit which locks out reprogramming of the authentication code,and a bit which indicates that the camera has been refilled by anauthenticated refill station. The flash memory can also be used to storeFPN correction data for the imaging array. Additionally, a phase lockedloop rescaling parameter is stored for scaling the clocking cycle to anappropriate correct time. The clock frequency does not require crystalaccuracy since no date functions are provided. To eliminate the cost ofa crystal, an on chip oscillator with a phase locked loop 224 is used.As the frequency of an on-chip oscillator is highly variable from chipto chip, the frequency ratio of the oscillator to the PLL is digitallytrimmed during initial testing. The value is stored in Flash memory 221.This allows the clock PLL to control the ink-jet heater pulse width withsufficient accuracy.

[0108] A scratchpad SRAM is a small static RAM 222 with a 6T cell. Thescratchpad provided temporary memory for the 16 bit CPU. 1024 bytes isadequate.

[0109] A print head interface 223 formats the data correctly for theprint head. The print head interface also provides all of the timingsignals required by the print head. These timing signals may varydepending upon temperature, the number of dots printed simultaneously,the print medium in the print roll, and the dye density of the ink inthe print roll.

[0110] The following is a table of external connections to the printhead interface: Connection Function Pins DataBits[0-7] Independentserial data to the eight 8 segments of the printhead BitClock Main dataclock for the print head 1 ColorEnable[0-2] Independent enable signalsfor the 3 CMY actuators, allowing different pulse times for each color.BankEnable[0-1] Allows either simultaneous or 2 interleaved actuation oftwo banks of nozzles. This allows two different print speed/powerconsumption tradeoffs NozzleSelect[0-4] Selects one of 32 banks ofnozzles 5 for simultaneous actuation ParallelXferClock Loads theparallel transfer register 1 with the data from the shift registersTotal 20

[0111] The printhead utilized is composed of eight identical segments,each 1.25 cm long. There is no connection between the segments on theprint head chip. Any connections required are made in the external TABbonding film, which is double sided. The division into eight identicalsegments is to simplify lithography using wafer steppers. The segmentwidth of 1.25 cm fits easily into a stepper field. As the printhead chipis long and narrow (10 cm×0.3 mm), the stepper field contains a singlesegment of 32 print head chips. The stepper field is therefore 1.25cm×1.6 cm. An average of four complete print heads are patterned in eachwafer step.

[0112] A single BitClock output line connects to all 8 segments on theprinthead. The 8 DataBits lines lead one to each segment, and areclocked into the 8 segments on the print head simultaneously (on aBitClock pulse). For example, dot 0 is transferred to segment₀, dot 750is transferred to segment₁, dot 1500 to segment₂ etc simultaneously.

[0113] The ParallelXferClock is connected to each of the 8 segments onthe printhead, so that on a single pulse, all segments transfer theirbits at the same time.

[0114] The NozzleSelect, BankEnable and ColorEnable lines are connectedto each of the 8 segments, allowing the print head interface toindependently control the duration of the cyan, magenta, and yellownozzle energizing pulses. Registers in the Print Head Interface allowthe accurate specification of the pulse duration between 0 and 6 ms,with a typical duration of 2 ms to 3 ms.

[0115] A parallel interface 125 connects the ICP to individual staticelectrical signals. The CPU is able to control each of these connectionsas memory mapped I/O via a low speed bus.

[0116] The following is a table of connections to the parallelinterface: Connection Direction Pins Paper transport stepper motorOutput 4 Capping solenoid Output 1 Copy LED Output 1 Photo button Input1 Copy button Input 1 Total 8

[0117] Seven high current drive transistors e.g. 227 are required. Fourare for the four phases of the main stepper motor two are for theguillotine motor, and the remaining transistor is to drive the cappingsolenoid. These transistors are allocated 20,000 square microns (600,000F) each. As the transistors are driving highly inductive loads, theymust either be turned off slowly, or be provided with a high level ofback EMF protection. If adequate back EMF protection cannot be providedusing the chip process chosen, then external discrete transistors shouldbe used. The transistors are never driven at the same time as the imagesensor is used. This is to avoid voltage fluctuations and hot spotsaffecting the image quality. Further, the transistors are located as faraway from the sensor as possible.

[0118] A standard JTAG (Joint Test Action Group) interface 228 isincluded in the ICP for testing purposes and for interrogation by therefill station. Due to the complexity of the chip, a variety of testingtechniques are required, including BIST (Built In Self Test) andfunctional block isolation. An overhead of 10% in chip area is assumedfor chip testing circuitry for the random logic portions. The overheadfor the large arrays the image sensor and the DRAM is smaller.

[0119] The JTAG interface is also used for authentication of the refillstation. This is included to ensure that the cameras are only refilledwith quality paper and ink at a properly constructed refill station,thus preventing inferior quality refills from occurring. The camera mustauthenticate the refill station, rather than vice versa. The secureprotocol is communicated to the refill station during the automated testprocedure. Contact is made to four gold plated spots on the ICP/printhead TAB by the refill station as the new ink is injected into the printhead.

[0120]FIG. 16 illustrates a rear view of the next step in theconstruction process whilst FIG. 17 illustrates a front view.

[0121] Turning now to FIG. 16, the assembly of the camera systemproceeds via first assembling the ink supply mechanism 40. The flex PCBis interconnected with batteries 84, only one of which is shown, whichare inserted in the middle portion of a print roll 85 which is wrappedaround a plastic former 86. An end cap 89 is provided at the other endof the print roll 85 so as to fasten the print roll and batteries firmlyto the ink supply mechanism.

[0122] The solenoid coil is interconnected (not shown) to interconnects97, 98 (FIG. 8) which include leaf spring ends for interconnection withelectrical contacts on the Flex PCB so as to provide for electricalcontrol of the solenoid.

[0123] Turning now to FIGS. 17-19 the next step in the constructionprocess is the insertion of the relevant gear trains into the side ofthe camera chassis. FIG. 17 illustrates a front view, FIG. 18illustrates a rear view and FIG. 19 also illustrates a rear view. Thefirst gear train comprising gear wheels 22, 23 is utilized for drivingthe guillotine blade with the gear wheel 23 engaging the gear wheel 65of FIG. 8. The second gear train comprising gear wheels 24, 25 and 26engage one end of the print roller 61 of FIG. 8. As best indicated inFIG. 18, the gear wheels mate with corresponding pins on the surface ofthe chassis with the gear wheel 26 being snap fitted into correspondingmating hole 27.

[0124] Next, as illustrated in FIG. 20, the assembled platten unit 60 isthen inserted between the print roll 85 and aluminum cutting blade 43.

[0125] Turning now to FIG. 21, by way of illumination, there isillustrated the electrically interactive components of the camerasystem. As noted previously, the components are based around a Flex PCBboard and include a TAB film 58 which interconnects the printhead 102with the image sensor and processing chip 48. Power is supplied by twoAA type batteries 83, 84 and a paper drive stepper motor 16 is providedin addition to a rotary guillotine motor 17.

[0126] An optical element 31 is provided for snapping into a top portionof the chassis 12. The optical element 31 includes portions defining anoptical view finder 32, 33 which are slotted into mating portions 35, 36in view finder channel 37. Also provided in the optical element 31 is alensing system 38 for magnification of the prints left number inaddition to an optical pipe element 39 for piping light from the LED 5for external display.

[0127] Turning next to FIG. 22, the assembled unit 90 is then insertedinto a front outer case 91 which includes button 4 for activation ofprintouts.

[0128] Turning now to FIG. 23, next, the unit 90 is provided with asnap-on back cover 93 which includes a slot 6 and copy print button 7. Awrapper label containing instructions and advertising (not shown) isthen wrapped around the outer surface of the camera system and pinchclamped to the cover by means of clamp strip 96 which can comprise aflexible plastic or rubber strip.

[0129] Subsequently, the preferred embodiment is ready for use as a onetime use camera system that provides for instant output images ondemand. It will be evident that the preferred embodiment furtherprovides for a refillable camera system. A used camera can be collectedand its outer plastic cases removed and recycled. A new paper roll andbatteries can be added and the ink cartridge refilled. A series ofautomatic test routines can then be carried out to ensure that theprinter is properly operational. Further, in order to ensure onlyauthorized refills are conducted so as to enhance quality, routines inthe on-chip program ROM can be executed such that the cameraauthenticates the refilling station using a secure protocol. Uponauthentication, the camera can reset an internal paper count and anexternal case can be fitted on the camera system with a new outer label.Subsequent packing and shipping can then take place.

[0130] It will be further readily evident to those skilled in the artthat the program ROM can be modified so as to allow for a variety ofdigital processing routines. In addition to the digitally enhancedphotographs optimized for mainstream consumer preferences, various othermodels can readily be provided through mere re-programming of theprogram ROM. For example, a sepia classic old fashion style output canbe provided through a remapping of the color mapping function. A furtheralternative is to provide for black and white outputs again through asuitable color remapping algorithm. Minimum color can also be providedto add a touch of color to black and white prints to produce the effectthat was traditionally used to colorize black and white photos. Further,passport photo output can be provided through suitable addressremappings within the address generators. Further, edge filters can beutilized as is known in the field of image processing to producesketched art styles. Further, classic wedding borders and designs can beplaced around an output image in addition to the provision of relevantclip arts. For example, a wedding style camera might be provided.Further, a panoramic mode can be provided so as to output the well knownpanoramic format of images. Further, a postcard style output can beprovided through the printing of postcards including postage on the backof a print roll surface. Further, cliparts can be provided for specialevents such as Halloween, Christmas etc. Further, kaleidoscopic effectscan be provided through address remappings and wild color effects can beprovided through remapping of the color lookup table. Many other formsof special event cameras can be provided for example, cameras dedicatedto the Olympics, movie tie-ins, advertising and other special events.

[0131] The operational mode of the camera can be programmed so that uponthe depressing of the take photo a first image is sampled by the sensorarray to determine irrelevant parameters. Next a second image is againcaptured which is utilized for the output. The captured image is thenmanipulated in accordance with any special requirements before beinginitially output on the paper roll. The LED light is then activated fora predetermined time during which the DRAM is refreshed so as to retainthe image. If the print copy button is depressed during thispredetermined time interval, a further copy of the photo is output.After the predetermined time interval where no use of the camera hasoccurred, the onboard CPU shuts down all power to the camera systemuntil such time as the take button is again activated. In this way,substantial power savings can be realized.

[0132] Ink Jet Technologies

[0133] The embodiments of the invention use an ink jet printer typedevice. Of course many different devices could be used. Howeverpresently popular ink jet printing technologies are unlikely to besuitable.

[0134] The most significant problem with thermal inkjet is powerconsumption. This is approximately 100 times that required for highspeed, and stems from the energy-inefficient means of drop ejection.This involves the rapid boiling of water to produce a vapor bubble whichexpels the ink. Water has a very high heat capacity, and must besuperheated in thermal inkjet applications. This leads to an efficiencyof around 0.02%, from electricity input to drop momentum (and increasedsurface area) out.

[0135] The most significant problem with piezoelectric inkjet is sizeand cost. Piezoelectric crystals have a very small deflection atreasonable drive voltages, and therefore require a large area for eachnozzle. Also, each piezoelectric actuator must be connected to its drivecircuit on a separate substrate. This is not a significant problem atthe current limit of around 300 nozzles per print head, but is a majorimpediment to the fabrication of pagewidth print heads with 19,200nozzles.

[0136] Ideally, the inkjet technologies used meet the stringentrequirements of in-camera digital color printing and other high quality,high speed, low cost printing applications. To meet the requirements ofdigital photography, new inkjet technologies have been created. Thetarget features include:

[0137] low power (less than 10 Watts)

[0138] high resolution capability (1,600 dpi or more)

[0139] photographic quality output

[0140] low manufacturing cost

[0141] small size (pagewidth times minimum cross section)

[0142] high speed (<2 seconds per page).

[0143] All of these features can be met or exceeded by the inkjetsystems described below with differing levels of difficulty. forty-fivedifferent inkjet technologies have been developed by the Assignee togive a wide range of choices for high volume manufacture. Thesetechnologies form part of separate applications assigned to the presentAssignee as set out in the table below.

[0144] The inkjet designs shown here are suitable for a wide range ofdigital printing systems, from battery powered one-time use digitalcameras, through to desktop and network printers, and through tocommercial printing systems For ease of manufacture using standardprocess equipment, the printhead is designed to be a monolithic 0.5micron CMOS chip with MEMS post processing. For color photographicapplications, the print head is 100 mm long, with a width which dependsupon the inkjet type. The smallest print head designed is IJ38, which is0.35 mm wide, giving a chip area of 35 square mm. The print heads eachcontain 19,200 nozzles plus data and control circuitry.

[0145] Ink is supplied to the back of the print head by injection moldedplastic ink channels. The molding requires 50 micron features, which canbe created using a lithographically micromachined insert in a standardinjection molding tool. Ink flows through holes etched through the waferto the nozzle chambers fabricated on the front surface of the wafer. Theprint head is connected to the camera circuitry by tape automatedbonding.

[0146] Cross-Referenced Applications

[0147] The following table is a guide to cross-referenced patentapplications filed concurrently herewith and discussed hereinafter withthe reference being utilized in subsequent tables when referring to aparticular case: Docket No. Reference Title IJ01US IJ01 Radiant PlungerInk Jet Printer IJ02US IJ02 Electrostatic Ink Jet Printer IJ03US IJ03Planar Thermoelastic Bend Actuator Ink Jet IJ04US IJ04 StackedElectrostatic Ink Jet Printer IJ05US IJ05 Reverse Spring Lever Ink JetPrinter IJ06US IJ06 Paddle Type Ink Jet Printer IJ07US IJ07 PermanentMagnet Electromagnetic Ink Jet Printer IJ08US IJ08 Planar Swing GrillElectromagnetic Ink Jet Printer IJ09US IJ09 Pump Action Refill Ink JetPrinter IJ10US IJ10 Pulsed Magnetic Field Ink Jet Printer IJ11US IJ11Two Plate Reverse Firing Electromagnetic Ink Jet Printer IJ12US IJ12Linear Stepper Actuator Ink Jet Printer IJ13US IJ13 Gear Driven ShutterInk Jet Printer IJ14US IJ14 Tapered Magnetic Pole Electromagnetic InkJet Printer IJ15US IJ15 Linear Spring Electromagnetic Grill Ink JetPrinter IJ16US IJ16 Lorenz Diaphragm Electromagnetic Ink Jet PrinterIJ17US IJ17 PTFE Surface Shooting Shuttered Oscillating Pressure Ink JetPrinter IJ18US IJ18 Buckle Grip Oscillating Pressure Ink Jet PrinterIJ19US IJ19 Shutter Based Ink Jet Printer IJ20US IJ20 Curling CalyxThermoelastic Ink Jet Printer IJ21US IJ21 Thermal Actuated Ink JetPrinter IJ22US IJ22 Iris Motion Ink Jet Printer IJ23US IJ23 DirectFiring Thermal Bend Actuator Ink Jet Printer IJ24US IJ24 Conductive PTFEBen Activator Vented Ink Jet Printer IJ25US IJ25 Magnetostrictive InkJet Printer IJ26US IJ26 Shape Memory Alloy Ink Jet Printer IJ27US IJ27Buckle Plate Ink Jet Printer IJ28US IJ28 Thermal Elastic Rotary ImpellerInk Jet Printer IJ29US IJ29 Thermoelastic Bend Actuator Ink Jet PrinterIJ30US IJ30 Thermoelastic Bend Actuator Using PTFE and Corrugated CopperInk Jet Printer IJ31US IJ31 Bend Actuator Direct Ink Supply Ink JetPrinter IJ32US IJ32 A High Young's Modulus Thermoelastic Ink Jet PrinterIJ33US IJ33 Thermally actuated slotted chamber wall ink jet printerIJ34US IJ34 Ink Jet Printer having a thermal actuator comprising anexternal coiled spring IJ35US IJ35 Trough Container Ink Jet PrinterIJ36US IJ36 Dual Chamber Single Vertical Actuator Ink Jet IJ37US IJ37Dual Nozzle Single Horizontal Fulcrum Actuator Ink Jet IJ38US IJ38 DualNozzle Single Horizontal Actuator Ink Jet IJ39US IJ39 A single bendactuator cupped paddle ink jet printing device IJ40US IJ40 A thermallyactuated ink jet printer having a series of thermal actuator unitsIJ41US IJ41 A thermally actuated ink jet printer including a taperedheater element IJ42US IJ42 Radial Back-Curling Thermoelastic Ink JetIJ43US IJ43 Inverted Radial Back-Curling Thermoelastic Ink Jet IJ44USIJ44 Surface bend actuator vented ink supply ink jet printer IJ45US IJ45Coil Acutuated Magnetic Plate Ink Jet Printer

[0148] Tables of Drop-on-Demand Inkjets

[0149] Eleven important characteristics of the fundamental operation ofindividual inkjet nozzles have been identified. These characteristicsare largely orthogonal, and so can be elucidated as an elevendimensional matrix. Most of the eleven axes of this matrix includeentries developed by the present assignee.

[0150] The following tables form the axes of an eleven dimensional tableof inkjet types.

[0151] Actuator mechanism (18 types)

[0152] Basic operation mode (7 types)

[0153] Auxiliary mechanism (8 types)

[0154] Actuator amplification or modification method (17 types)

[0155] Actuator motion (19 types)

[0156] Nozzle refill method (4 types)

[0157] Method of restricting back-flow through inlet (10 types)

[0158] Nozzle clearing method (9 types)

[0159] Nozzle plate construction (9 types)

[0160] Drop ejection direction (5 types)

[0161] Ink type (7 types)

[0162] The complete eleven dimensional table represented by these axescontains 36.9 billion possible configurations of inkjet nozzle. Whilenot all of the possible combinations result in a viable inkjettechnology, many million configurations are viable. It is clearlyimpractical to elucidate all of the possible configurations. Instead,certain inkjet types have been investigated in detail. These aredesignated IJ01 to IJ45 above.

[0163] Other inkjet configurations can readily be derived from theseforty-five examples by substituting alternative configurations along oneor more of the eleven axes. Most of the IJ01 to IJ45 examples can bemade into inkjet print heads with characteristics superior to anycurrently available inkjet technology.

[0164] Where there are prior art examples known to the inventor, one ormore of these examples are listed in the examples column of the tablesbelow. The IJ01 to IJ45 series are also listed in the examples column.In some cases, a printer may be listed more than once in a table, whereit shares characteristics with more than one entry.

[0165] Suitable applications include: Home printers, Office networkprinters, Short run digital printers, Commercial print systems, Fabricprinters, Pocket printers, Internet WWW printers, Video printers,Medical imaging, Wide format printers, Notebook PC printers, Faxmachines, Industrial printing systems, Photocopiers, Photographicminilabs etc.

[0166] The information associated with the aforementioned elevendimensional matrix are set out in the following tables. ACTUATORMECHANISM (APPLIED ONLY TO SELECTED INK DROPS) Actuator MechanismDescription Advantages Disadvantages Examples Thermal bubble Anelectrothermal heater Large force generated High power Canon Bubblejet1979 heats the ink to Simple construction Ink carrier limited Endo et alGB patent above boiling point, No moving parts to water 2,007,162transferring significant Fast operation Low efficiency Xeroxheater-in-pit 1990 heat to the aqueous ink. Small chip area required forHigh temperatures Hawkins et al U.S. Pat. No. A bubble nucleates andactuator required 4,899,181 quickly forms, expelling High mechanicalHewlett-Packard TIJ the ink. The efficiency stress 1982 Vaught et al ofthe process is low, Unusual materials U.S. Pat. No. 4,490,728 withtypically less than required 0.05% of the electrical Large drive energybeing transformed transistors into kinetic energy of Cavitation causesthe drop. actuator failure Kogation reduces bubble formation Large printheads are difficult to fabricate Piezoelectric A piezoelectric Low powerconsumption Very large area Kyser et al U.S. Pat. No. crystal such aslead Many ink types can be used required for 3,946,398 lanthanumzirconate Fast operation actuator Zoltan U.S. Pat. No. 3,683,212 (PZT)is electrically High efficiency Difficult to 1973 Stemme U.S. Pat. No.activated, and either integrate with 3,747,120 expands, shears, orelectronics Epson Stylus bends to apply pressure High voltage driveTektronix to the ink, ejecting transistors required IJ04 drops. Fullpagewidth print heads impractical due to actuator size Requireselectrical poling in high field strengths during manufactureElectro-strictive An electric field is Low power consumption Low maximumstrain Seiko Epson, Usui et all used to activate Many ink types can beused (approx. 0.01%) JP 253401/96 electrostriction in Low thermalexpansion Large area required IJ04 relaxor materials such Electric fieldstrength required for actuator due to as lead lanthanum (approx. 3.5V/μm) can be low strain zirconate titanate generated without difficultyResponse speed is (PLZT) or lead Does not require electrical marginal(˜10 μs) magnesium niobate poling High voltage drive (PMN). transistorsrequired Full pagewidth print heads impractical due to actuator sizeFerroelectric An electric field is Low power consumption Difficult toIJ04 used to induce a Many ink types can be used integrate with phasetransition Fast operation (<1 μs) electronics between the Relativelyhigh longitudinal Unusual materials antiferroelectric strain such asPLZSnT are (AFE) and ferroelectric High efficiency required (FE) phase.Perovskite Electric field strength of around Actuators require materialssuch as 3 V/μm can be readily a large area tin modified lead providedlanthanum zirconate titanate (PLZSnT) exhibit large strains of up to 1%associated with the AFE to FE phase transition. Electrostatic Conductiveplates are Low power consumption Difficult to operate IJ02, IJ04 platesseparated by a Many ink types can be used electrostatic devicescompressible or fluid Fast operation in an aqueous dielectric (usuallyenvironment air). Upon application The electrostatic of a voltage, theactuator will normally plates attract each need to be separated otherand displace ink, from the ink causing drop ejection. Very large areaThe conductive plates required to achieve may be in a comb or highforces honeycomb structure, or High voltage drive stacked to increasethe transistors may be surface area and required therefore the force.Full pagewidth print heads are not competitive due to actuator sizeElectrostatic pull A strong electric field Low current consumption Highvoltage required 1989 Saito et al, U.S. Pat. No. on ink is applied tothe Low temperature May be damaged by 4,799,068 ink, whereupon sparksdue to air 1989 Miura et al, U.S. Pat. No. electrostatic attractionbreakdown 4,810,954 accelerates the ink Required field Tone-jet towardsthe print strength increases medium. as the drop size decreases Highvoltage drive transistors required Electrostatic field attracts dustPermanent An electromagnet Low power consumption Complex fabricationIJ07, IJ10 magnet electro- directly attracts a Many ink types can beused Permanent magnetic magnetic permanent magnet, Fast operationmaterial such as displacing ink and High efficiency Neodymium Iron Boroncausing drop ejection. Easy extension from single (NdFeB) required. Rareearth magnets nozzles to pagewidth print High local currents with afield strength heads required around 1 Tesla can be Copper metalizationused. Examples are: should be used for Samarium Cobalt longelectromigration (SaCo) and magnetic lifetime and low materials in theresistivity neodymium iron boron Pigmented inks are family (NdFeB,usually infeasible NdDyFeBNb, NdDyFeB, etc) Operating temperaturelimited to the Curie temperature (around 540 K) Soft magnetic core Asolenoid induced a Low power consumption Complex fabrication IJ01, IJ05,IJ08, IJ10 electro-magnetic magnetic field in a Many ink types can beused Materials not usually IJ12, IJ14, IJ15, IJ17 soft magnetic core orFast operation present in a CMOS fab yoke fabricated from a Highefficiency such as NiFe, CoNiFe, ferrous material such as Easy extensionfrom single or CoFe are electroplated iron nozzles to pagewidth printrequired alloys such as CoNiFe heads High local currents [1], CoFe, orNiFe required alloys. Typically, the Copper metalization soft magneticmaterial should be used for is in two parts, long electromigration whichare normally held lifetime and low apart by a spring. When resistivitythe solenoid is actuated, Electroplating is the two parts attract,required displacing the ink. High saturation flux density is required(2.0-2.1 T is achievable with CoNiFe [1]) Magnetic The Lorenz forceacting Low power consumption Force acts as a IJ06, IJ11, IJ13, IJ16Lorenz force on a current carrying Many ink types can be used twistingmotion wire in a magnetic field Fast operation Typically, only a isutilized. High efficiency quarter of the sole- This allows the Easyextension from single noid length provides magnetic field to be nozzlesto pagewidth print force in a useful supplied externally to headsdirection the print head, for High local currents example with rareearth required permanent magnets. Copper metalization Only the currentshould be used for carrying wire need be long electromigrationfabricated on the print- lifetime and low head, simplifying resistivitymaterials requirements. Pigmented inks are usually infeasibleMagneto-striction The actuator uses the Many ink types can be used Forceacts as a Fischenbeck, U.S. Pat. No. giant magnetostrictive Fastoperation twisting motion 4,032,929 effect of materials such Easyextension from single Unusual materials IJ25 as Terfenol-D (an nozzlesto pagewidth print such as Terfenol-D alloy of terbium, heads arerequired dysprosium and iron High force is available High local currentsdeveloped at the required Naval Ordnance Copper metalization Laboratory,hence Ter- should be used for Fe-NOL). For best long electromigrationefficiency, the lifetime and low actuator should be resistivitypre-stressed to Pre-stressing may approx. 8 MPa. be required Surfacetension Ink under positive Low power consumption Requires supplementarySilverbrook, EP 0771 reduction pressure is held in Simple constructionforce to effect drop 658 A2 and related a nozzle by surface No unusualmaterials required separation patent applications tension. The surfacein fabrication Requires special ink tension of the ink is Highefficiency surfactants reduced below the Easy extension from singleSpeed may be limited bubble threshold, nozzles to pagewidth print bysurfactant causing the ink to heads properties egress from the nozzle.Viscosity The ink viscosity is Simple construction Requiressupplementary Silverbrook, EP 0771 reduction locally reduced to Nounusual materials required force to effect drop 658 A2 and relatedselect which drops in fabrication separation patent applications are tobe ejected. A Easy extension from single Requires special ink viscosityreduction nozzles to pagewidth print viscosity properties can beachieved heads High speed is electrothermally with difficult to achievemost inks, but Requires oscillating special inks can be ink pressureengineered for a 100:1 A high temperature viscosity reduction.difference (typically 80 degrees) is required Acoustic An acoustic waveis Can operate without a nozzle Complex drive circuitry 1993 Hadimiogluet al, generated and plate Complex fabrication EUP 550,192 focussed uponthe Low efficiency 1993 Elrod et al, EUP drop ejection region. Poorcontrol of drop 572,220 position Poor control of drop volumeThermoelastic An actuator which Low power consumption Efficient aqueousIJ03, IJ09, IJ17, IJ18 bend actuator relies upon Many ink types can beused operation requires IJ19, IJ20, IJ21, IJ22 differential thermalSimple planar fabrication a thermal insulator IJ23, IJ24, IJ27, IJ28expansion upon Small chip area required for on the hot side IJ29, IJ30,IJ31, IJ32 Joule heating is used. each actuator Corrosion preventionIJ33, IJ34, IJ35, IJ36 Fast operation can be difficult IJ37, IJ38, IJ39,IJ40 High efficiency Pigmented inks may IJ41 CMOS compatible voltagesand be infeasible, as currents pigment particles Standard MEMS processescan may jam the bend be used actuator Easy extension from single nozzlesto pagewidth print heads High CTE A material with a very High force canbe generated Requires special IJ09, IJ17, IJ18, IJ20 thermoelastic highcoefficient of PTFE is a candidate for low material (e.g. PTFE) IJ21,IJ22, IJ23, IJ24 actuator thermal expansion (CTE) dielectric constantinsulation Requires a PTFE IJ27, IJ28, IJ29, IJ30 such as in ULSIdeposition process, IJ31, IJ42, IJ43, IJ44 polytetrafluoroethylene Verylow power consumption which is not yet (PTFE) is used. Many ink typescan be used standard in ULSI fabs As high CTE materials Simple planarfabrication PTFE deposition are usually non- Small chip area requiredfor cannot be followed conductive, a heater each actuator with hightemperature fabricated from a Fast operation (above 350 °C.) conductivematerial High efficiency processing is incorporated. A 50 CMOScompatible voltages and Pigmented inks may μm long PTFE bend currents beinfeasible, as actuator with Easy extension from single pigmentparticles polysilicon heater nozzles to pagewidth print may jam the bendand 15 mW power heads actuator input can provide 180 μN force and 10 μmdeflection. Actuator motions include: Bend Push Buckle Rotate ConductiveA polymer with a High force can be generated Requires special IJ24polymer high coefficient of Very low power consumption materialsdevelopment thermoelastic thermal expansion Many ink types can be used(High CTE conductive actuator (such as PTFE) is Simple planarfabrication polymer) doped with conducting Small chip area required forRequires a PTFE substances to each actuator deposition process, increaseits Fast operation which is not yet conductivity to about Highefficiency standard in ULSI fabs 3 orders of magnitude CMOS compatiblevoltages and PTFE deposition cannot below that of currents be followedwith high copper. The conducting Easy extension from single temperature(above polymer expands nozzles to pagewidth print 350 °C.) processingwhen resistively heated. heads Evaporation and CVD Examples ofconducting deposition techniques dopants include: cannot be used Carbonnanotubes Pigmented inks may Metal fibers be infeasible, as Conductivepolymers pigment particles such as doped may jam the bend polythiopheneactuator Carbon granules Shape memory A shape memory alloy High force isavailable (stresses Fatigue limits IJ26 alloy such as TiNi (also ofhundreds of MPa) maximum number of known as Nitinol - Large strain isavailable (more cycles Nickel Titanium alloy than 3%) Low strain (1%) isdeveloped at the High corrosion resistance required to extend NavalOrdnance Simple construction fatigue resistance Laboratory) is Easyextension from single Cycle rate limited thermally switched nozzles topagewidth print by heat removal between its weak heads Requires unusualmartensitic state and Low voltage operation materials (TiNi) its highstiffness The latent heat of austenic state. The transformation mustshape of the actuator be provided in its martensitic High currentoperation state is deformed Requires pre-stressing relative to the todistort the austenic shape. martensitic state The shape change causesejection of a drop. Linear Magnetic Linear magnetic Linear Magneticactuators can Requires unusual semi- IJ12 Actuator actuators include thebe constructed with high conductor materials Linear Induction thrust,long travel, and high such as soft magnetic Actuator (LIA), Linearefficiency using planar alloys (e.g. CoNiFe Permanent Magnetsemiconductor fabrication [1]) Synchronous Actuator techniques Somevarieties also (LPMSA), Linear Long actuator travel is available requirepermanent Reluctance Synchronous Medium force is available magneticmaterials Actuator (LRSA), Linear Low voltage operation such asNeodymium Switched Reluctance iron boron (NdFeB) Actuator (LSRA),Requires complex and the Linear Stepper multi-phase drive Actuator(LSA). circuitry High current operation

[0167] BASIC OPERATION MODE Operational mode Description AdvantagesDisadvantages Examples Actuator directly This is the simplest Simpleoperation Drop repetition rate is usually limited to less Thermal inkjetpushes ink mode of operation: No external fields required than 10 KHz.However, this is not Piezoelectric inkjet the actuator directlySatellite drops can be avoided if fundamental to the method, but isrelated IJ01, IJ02, IJ03, IJ04 supplies sufficient drop velocity is lessthan 4 to the refill method normally used IJ05, IJ06, IJ07, IJ09 kineticenergy to m/s All of the drop kinetic energy must be IJ11, IJ12, IJ14,IJ16 expel the drop. The Can be efficient, depending provided by theactuator IJ20, IJ22, IJ23, IJ24 drop must have a upon the actuator usedSatellite drops usually form if drop velocity IJ25, IJ26, IJ27, IJ28sufficient velocity is greater than 4.5 m/s IJ29, IJ30, IJ31, IJ32 toovercome the IJ33, IJ34, IJ35, IJ36 surface tension. IJ37, IJ38, IJ39,IJ40 IJ41, IJ42, IJ43, IJ44 Proximity The drops to be Very simple printhead Requires close proximity between the print Silverbrook, EP 0771printed are selected fabrication can be used head and the print media ortransfer roller 658 A2 and related by some manner (e.g. The dropselection means does May require two print heads printing patentapplications thermally induced not need to provide the alternate rows ofthe image surface tension energy required to separate Monolithic colorprint heads are difficult reduction of pressur- the drop from the nozzleized ink). Selected drops are separated from the ink in the nozzle bycontact with the print medium or a transfer roller. Electrostatic pullThe drops to be printed Very simple print head Requires very highelectrostatic field Silverbrook, EP 0771 on ink are selected byfabrication can be used Electrostatic field for small nozzle sizes is658 A2 and related some manner (e.g. The drop selection means does aboveair breakdown patent applications thermally induced not need to providethe Electrostatic field may attract dust Tone-Jet surface tension energyrequired to separate reduction of pressur- the drop from the nozzle izedink). Selected drops are separated from the ink in the nozzle by astrong electric field. Magnetic pull on The drops to be Very simpleprint head Requires magnetic ink Silverbrook, EP 0771 ink printed areselected fabrication can be used Ink colors other than black aredifficult 658 A2 and related by some manner (e.g. The drop selectionmeans does Requires very high magnetic fields patent applicationsthermally induced not need to provide the surface tension energyrequired to separate reduction of pressur- the drop from the nozzle izedink). Selected drops are separated from the ink in the nozzle by astrong magnetic field acting on the magnetic ink. Shutter The actuatormoves a High speed (>50 KHz) Moving parts are required IJ13, IJ17, IJ21shutter to block ink operation can be achieved Requires ink pressuremodulator flow to the nozzle. due to reduced refill time Friction andwear must be considered The ink pressure is Drop timing can be veryStiction is possible pulsed at a multiple accurate of the drop ejectionThe actuator energy can be frequency. very low Shuttered grill Theactuator moves a Actuators with small travel can Moving parts arerequired IJ08, IJ15, IJ18, IJ19 shutter to block ink be used Requiresink pressure modulator flow through a grill Actuators with small forcecan Friction and wear must be considered to the nozzle. The be usedStiction is possible shutter movement need High speed (>50 KHz) only beequal to operation can be achieved the width of the grill holes. Pulsedmagnetic A pulsed magnetic Extremely low energy operation Requires anexternal pulsed magnetic field IJ10 pull on ink pusher field attracts an‘ink is possible Requires special materials for both the pusher’ at thedrop No heat dissipation problems actuator and the ink pusher ejectionfrequency. Complex construction An actuator controls a catch, whichprevents the ink pusher from moving when a drop is not to be ejected.

[0168] AUXILIARY MECHANISM (APPLIED TO ALL NOZZLES) Auxiliary MechanismDescription Advantages Disadvantages Examples None The actuator directlySimplicity of construction Drop ejection energy must be supplied Mostinkjets, including fires the ink drop, Simplicity of operation byindividual nozzle actuator piezoelectric and and there is no Smallphysical size thermal bubble. external field or other IJ01-IJ07, IJ09,IJ11 mechanism required. IJ12, IJ14, IJ20, IJ22 IJ23-IJ45 Oscillatingink The ink pressure Oscillating ink pressure can Requires external inkpressure oscillator Silverbrook, EP 0771 pressure oscillates, providingprovide a refill pulse, Ink pressure phase and amplitude must 658 A2 andrelated (including much of the drop allowing higher operating becarefully controlled patent applications acoustic ejection energy. Thespeed Acoustic reflections in the ink chamber IJ08, IJ13, IJ15, IJ17stimulation) actuator selects The actuators may operate with must bedesigned for IJ18, IJ19, IJ21 which drops are to be much lower energyfired by selectively Acoustic lenses can be used to blocking or enablingfocus the sound on the nozzles. The ink nozzles pressure oscillation maybe achieved by vibrating the print head, or preferably by an actuator inthe ink supply. Media proximity The print head is Low power Precisionassembly required Silverbrook, EP 0771 placed in close High accuracyPaper fibers may cause problems 658 A2 and related proximity to theSimple print head construction Cannot print on rough substrates patentapplications print medium. Selected drops protrude from the print headfurther than unselected drops, and contact the print medium. The dropsoaks into the medium fast enough to cause drop separation. Transferroller Drops are printed to High accuracy Bulky Silverbrook, EP 0771 atransfer roller Wide range of print substrates Expensive 658 A2 andrelated instead of straight can be used Complex construction patentapplications to the print medium. Ink can be dried on the transferTektronix hot melt A transfer roller roller piezoelectric inkjet canalso be used for Any of the IJ series proximity drop separation.Electrostatic An electric field is Low power Field strength required forseparation Silverbrook, EP 0771 used to accelerate Simple print headconstruction of small drops is near or above air 658 A2 and relatedselected drops towards breakdown patent applications the print medium.Tone-Jet Direct magnetic A magnetic field is Low power Requires magneticink Silverbrook, EP 0771 field used to accelerate Simple print headconstruction Requires strong magnetic field 658 A2 and related selecteddrops of patent applications magnetic ink towards the print medium.Cross magnetic The print head is Does not require magnetic Requiresexternal magnet IJ06, IJ16 field placed in a constant materials to beintegrated in Current densities may be high, resulting magnetic field.The the print head manufacturing in electromigration problems Lorenzforce in a process current carrying wire is used to move the actuator.Pulsed magnetic A pulsed magnetic Very low power operation is Complexprint head construction IJ10 field field is used to possible Magneticmaterials required in print head cyclically attract a Small print headsize paddle, which pushes on the ink. A small actuator moves a catch,which selectively prevents the paddle from moving.

[0169] ACTUATOR AMPLIFICATION OR MODIFICATION METHOD Actuatoramplification Description Advantages Disadvantages Examples None Noactuator mechanical Operational simplicity Many actuator mechanisms haveinsuf- Thermal Bubble InkJet amplification is ficient travel, orinsufficient force, IJ01, IJ02, IJ06, IJ07 used. The actuator toefficiently drive the drop ejection IJ16, IJ25, IJ26 directly drives theprocess drop ejection process. Differential An actuator materialProvides greater travel in a High stresses are involved Piezoelectricexpansion bend expands more on reduced print head area Care must betaken that the materials IJ03, IJ09, IJ17-IJ24 actuator one side than onThe bend actuator converts a do not delaminate IJ27 IJ29-IJ39, IJ42, theother. The high force low travel actuator Residual bend resulting fromhigh IJ43, IJ44 expansion may be mechanism to high travel, temperatureor high stress during thermal, piezoelectric, lower force mechanism.formation magnetostrictive, or other mechanism. Transient bend Atrilayer bend Very good temperature stability High stresses are involvedIJ40, IJ41 actuator actuator where the two High speed, as a new drop canCare must be taken that the materials outside layers are be fired beforeheat dissipates do not delaminate identical. This cancels Cancelsresidual stress of bend due to ambient formation temperature andresidual stress. The actuator only responds to transient heating of oneside or the other. Actuator stack A series of thin Increased travelIncreased fabrication complexity Some piezoelectric ink actuators arestacked. Reduced drive voltage Increased possibility of short circuitsjets This can be due to pinholes IJ04 appropriate where actuatorsrequire high electric field strength, such as electrostatic andpiezoelectric actuators. Multiple actuators Multiple smaller Increasesthe force available Actuator forces may not add linearly, IJ12, IJ13,IJ18, IJ20 actuators are used from an actuator reducing efficiency IJ22,IJ28, IJ42, IJ43 simultaneously to Multiple actuators can be move theink. Each positioned to control ink flow actuator need accuratelyprovide only a portion of the force required. Linear Spring A linearspring is Matches low travel actuator Requires print head area for thespring IJ15 used to transform a with higher travel motion with smallrequirements travel and high force Non-contact method of motion into alonger travel, transformation lower force motion. Reverse spring Theactuator loads a Better coupling to the ink Fabrication complexity IJ05,IJ11 spring. When the High stress in the spring actuator is turned off,the spring releases. This can reverse the force/distance curve of theactuator to make it compatible with the force/time requirements of thedrop ejection. Coiled actuator A bend actuator is Increases travelGenerally restricted to planar IJ17, IJ21, IJ34, IJ35 coiled to provideReduces chip area implementations due to extreme greater travel in aPlanar implementations are fabrication difficulty in other reduced chiparea. relatively easy to fabricate. orientations. Flexure bend A bendactuator has Simple means of increasing Care must be taken not to exceedthe IJ10, IJ19, IJ33 actuator a small region near travel of a bendactuator elastic limit in the flexure area the fixture point, Stressdistribution is very uneven which flexes much Difficult to accuratelymodel with finite more readily than element analysis the remainder ofthe actuator. The actuator flexing is effectively converted from an evencoiling to an angular bend, resulting in greater travel of the actuatortip. Gears Gears can be used to Low force, low travel actuators Movingparts are required IJ13 increase travel at can be used Several actuatorcycles are required the expense of Can be fabricated using More complexdrive electronics duration. Circular standard surface MEMS Complexconstruction gears, rack and pinion, processes Friction, friction, andwear are possible ratchets, and other gearing methods can be used. CatchThe actuator controls Very low actuator energy Complex construction IJ10a small catch. The Very small actuator size Requires external forcecatch either enables Unsuitable for pigmented inks or disables movementof an ink pusher that is controlled in a bulk manner. Buckle plate Abuckle plate can be Very fast movement achievable Must stay withinelastic limits of the S. Hirata et al, “An Ink- used to change amaterials for long device life jet Head . . . ”, Proc. slow actuatorinto a High stresses involved IEEE MEMS, February fast motion. It canGenerally high power requirement 1996, pp 418-423. also convert a highIJ18, IJ27 force, low travel actuator into a high travel, medium forcemotion. Tapered magnetic A tapered magnetic Linearizes the magneticComplex construction IJ14 pole pole can increase force/distance curvetravel at the expense of force. Lever A lever and fulcrum Matches lowtravel actuator High stress around the fulcrum IJ32, IJ36, IJ37 is usedto transform with higher travel a motion with small requirements traveland high force Fulcrum area has no linear into a motion with movement,and can be used longer travel and for a fluid seal lower force. Thelever can also reverse the direction of travel. Rotary impeller Theactuator is High mechanical advantage Complex construction IJ28connected to a rotary The ratio of force to travel of Unsuitable forpigmented inks impeller. A small the actuator can be matched angulardeflection of to the nozzle requirements by the actuator results varyingthe number of in a rotation of the impeller vanes impeller vanes, whichpush the ink against stationary vanes and out of the nozzle. Acousticlens A refractive or No moving parts Large area required 1993 Hadimiogluet al, diffractive (e.g. zone Only relevant for acoustic ink jets EUP550,192 plate) acoustic lens 1993 Elrod et al, EUP is used toconcentrate 572,220 sound waves. Sharp conductive A sharp point is usedSimple construction Difficult to fabricate using standard Tone-jet pointto concentrate an VLSI processes for a surface ejecting electrostaticfield. ink-jet Only relevant for electrostatic ink jets

[0170] ACTUATOR MOTION Actuator motion Description AdvantagesDisadvantages Examples Volume The volume of the Simple construction Highenergy is typically required to Hewlett-Packard expansion actuatorchanges, in the case achieve volume expansion. This leads to ThermalInkJet pushing the ink in of thermal ink jet thermal stress, cavitation,and kogation Canon Bubblejet all directions. in thermal ink jetimplementations Linear, The actuator moves in Efficient coupling Highfabrication complexity may be IJ01, IJ02, IJ04, IJ07 normal to adirection normal to ink drops required to achieve perpendicular motionIJ11, IJ14 chip surface to the print head ejected normal to surface. Thenozzle the surface is typically in the line of movement. Linear, Theactuator moves Suitable for planar Fabrication complexity IJ12, IJ13,IJ15, IJ33, parallel to parallel to the print fabrication Friction IJ34,IJ35, IJ36 chip surface head surface. Drop Stiction ejection may stillbe normal to the surface. Membrane push An actuator with a The effectiveFabrication complexity 1982 Howkins U.S. Pat. No. high force but smallarea of the Actuator size 4,459,601 area is used to push actuatorbecomes Difficulty of integration in a VLSI a stiff membrane that themembrane area process is in contact with the ink. Rotary The actuatorcauses Rotary levers may Device complexity IJ05, IJ08, IJ13, IJ28 therotation of some be used to May have friction at a pivot point element,such a grill increase travel or impeller Small chip area requirementsBend The actuator bends A very small Requires the actuator to be madefrom 1970 Kyser et al U.S. Pat. No. when energized. This change in atleast two distinct layers, or to 3,946,398 may be due to dimensions canhave a thermal difference across the 1973 Stemme U.S. Pat. No.differential thermal be converted actuator 3,747,120 expansion, piezo-to a large IJ03, IJ09, IJ10, IJ19 electric expansion, motion. IJ23,IJ24, IJ25, IJ29 magnetostriction, IJ30, IJ31, IJ33, IJ34 or other formof IJ35 relative dimensional change. Swivel The actuator swivels Allowsoperation Inefficient coupling to the ink motion IJ06 around a centralwhere the net pivot. This motion is linear force on suitable where therethe paddle is are opposite forces zero applied to opposite Small chiparea sides of the paddle, requirements e.g. Lorenz force. Straighten Theactuator is Can be used Requires careful balance of stresses to IJ26,IJ32 normally bent, and with shape ensure that the quiescent bend isstraightens when memory alloys accurate energized. where the austenicphase is planar Double bend The actuator bends in One actuator canDifficult to make the drops ejected by IJ36, IJ37, IJ38 one directionwhen one be used to power both bend directions identical. element isenergized, two nozzles. A small efficiency loss compared to and bendsthe other way Reduced chip size. equivalent single bend actuators. whenanother element is Not sensitive to energized. ambient temperature ShearEnergizing the actuator Can increase the Not readily applicable to otheractuator 1985 Fishbeck U.S. Pat. No. causes a shear motion in effectivetravel mechanisms 4,584,590 the actuator material. of piezoelectricactuators Radial The actuator squeezes Relatively easy High forcerequired 1970 Zoltan U.S. Pat. No. constriction an ink reservoir, tofabricate Inefficient 3,683,212 forcing ink from a single nozzlesDifficult to integrate with VLSI constricted nozzle. from glassprocesses tubing as macroscopic structures Coil/uncoil A coiled actuatorEasy to fabricate Difficult to fabricate for non-planar IJ17, IJ21,IJ34, IJ35 uncoils or coils more as a planar devices tightly. The motionof VLSI process Poor out-of-plane stiffness the free end of the Smallarea actuator ejects the ink. required, therefore low cost Bow Theactuator bows (or Can increase the Maximum travel is constrained IJ16,IJ18, IJ27 buckles) in the speed of travel High force required middlewhen energized. Mechanically rigid Push-Pull Two actuators control Thestructure is Not readily suitable for inkjets which IJ18 a shutter. Onepinned at both directly push the ink actuator pulls the ends, so has ashutter, and the other high out-of- pushes it. plane rigidity Curlinwards A set of actuators curl Good fluid flow Design complexity IJ20,IJ42 inwards to reduce to the region the volume of ink that behind thethey enclose. actuator increases efficiency Curl outwards A set ofactuators Relatively simple Relatively large chip area IJ43 curloutwards, construction pressurizing ink in a chamber surrounding theactuators, and expelling ink from a nozzle in the chamber. Iris Multiplevanes enclose High efficiency High fabrication complexity IJ22 a volumeof ink. These Small chip area Not suitable for pigmented inkssimultaneously rotate, reducing the volume between the vanes. Acousticvibration The actuator vibrates The actuator can Large area required forefficient 1993 Hadimioglu et al, at a high frequency. be physicallyoperation at useful frequencies EUP 550,192 distant from the Acousticcoupling and crosstalk 1993 Elrod et al, EUP ink Complex drive circuitry572,220 Poor control of drop volume and position None In various ink jetNo moving parts Various other tradeoffs are required Silverbrook, EP0771 designs the actuator to eliminate moving parts 658 A2 and relateddoes not move. patent applications Tone-jet

[0171] NOZZLE REFILL METHOD Nozzle refill method Description AdvantagesDisadvantages Examples Surface tension After the actuator Fabricationsimplicity Low speed Thermal inkjet is energized, it Operationalsimplicity Surface tension force relatively small Piezoelectric inkjettypically returns compared to actuator force IJ01-IJ07, IJ10-IJ14rapidly to its normal Long refill time usually dominates the IJ16, IJ20,IJ22-IJ45 position. This rapid total repetition rate return sucks in airthrough the nozzle opening. The ink surface tension at the nozzle thenexerts a small force restoring the meniscus to a minimum area. ShutteredInk to the nozzle High speed Requires common ink pressure oscillatorIJ08, IJ13, IJ15, IJ17 oscillating ink chamber is provided Low actuatorenergy, as the May not be suitable for pigmented inks IJ18, IJ19, IJ21pressure at a pressure that actuator need only open or oscillates attwice close the shutter, instead of the drop ejection ejecting the inkdrop frequency. When a drop is to be ejected, the shutter is opened for3 half cycles: drop ejection, actuator return, and refill. Refillactuator After the main actuator High speed, as the nozzle is Requirestwo independent actuators per IJ09 has ejected a drop a activelyrefilled nozzle second (refill) actuator is energized. The refillactuator pushes ink into the nozzle chamber. The refill actuator returnsslowly, to prevent its return from emptying the chamber again. Positiveink The ink is held a slight High refill rate, therefore a Surface spillmust be prevented Silverbrook, EP 0771 pressure positive pressure. Afterhigh drop repetition rate is Highly hydrophobic print head surfaces 658A2 and related the ink drop is ejected, possible are required patentapplications the nozzle chamber fills Alternative for: quickly assurface IJ01-IJ07, IJ10-IJ14 tension and ink pressure IJ16, IJ20,IJ22-IJ45 both operate to refill the nozzle.

[0172] METHOD OF RESTRICTING BACK-FLOW THROUGH INLET Inlet back-flowrestriction method Description Advantages Disadvantages Examples Longinlet The ink inlet channel Design simplicity Restricts refill rateThermal inkjet channel to the nozzle chamber Operational simplicity Mayresult in a relatively large chip Piezoelectric inkjet is made long andReduces crosstalk area IJ42, IJ43 relatively narrow, Only partiallyeffective relying on viscous drag to reduce inlet back-flow. Positiveink The ink is under a Drop selection and separation Requires a method(such as a nozzle rim Silverbrook, EP 0771 pressure positive pressure,forces can be reduced or effective hydrophobizing, or both) to 658 A2and related so that in the Fast refill time prevent flooding of theejection surface patent applications quiescent state some of the printhead. Possible operation of the of the ink drop already following:protrudes from the IJ01-IJ07, IJ09-IJ12 nozzle. This reduces IJ14, IJ16,IJ20, IJ22, the pressure in the IJ23-IJ34, IJ36-IJ41 nozzle chamberwhich IJ44 is required to eject a certain volume of ink. The reductionin chamber pressure results in a reduction in ink pushed out through theinlet. Baffle One or more baffles The refill rate is not as Designcomplexity HP Thermal Ink Jet are placed in the restricted as the longMay increase fabrication complexity Tektronix piezoelectric inlet inkflow. When inlet method. (e.g. Tektronix hot melt Piezoelectric inkjetthe actuator is Reduces crosstalk print heads). energized, the rapid inkmovement creates eddies which restrict the flow through the inlet. Theslower refill process is unre- stricted, and does not result in eddies.Flexible flap In this method Significantly reduces back-flow Notapplicable to most inkjet config- Canon restricts inlet recentlydisclosed by for edge-shooter thermal ink urations Canon, the expandingjet devices Increased fabrication complexity actuator (bubble) Inelasticdeformation of polymer flap pushes on a flexible results in creep overextended use flap that restricts the inlet. Inlet filter A filter islocated Additional advantage of ink Restricts refill rate IJ04, IJ12,IJ24, IJ27 between the ink inlet filtration May result in complexconstruction IJ29, IJ30 and the nozzle chamber. Ink filter may befabricated The filter has a with no additional process multitude ofsmall steps holes or slots, restricting ink flow. The filter alsoremoves particles which may block the nozzle. Small inlet The ink inletchannel Design simplicity Restricts refill rate IJ02, IJ37, IJ44compared to to the nozzle chamber May result in a relatively large chipnozzle has a substantially area smaller cross section Only partiallyeffective than that of the nozzle, resulting in easier ink egress out ofthe nozzle than out of the inlet. Inlet shutter A secondary actuatorIncreases speed of the ink- Requires separate refill actuator and IJ09controls the position jet print head operation drive circuit of ashutter, closing off the ink inlet when the main actuator is energized.The inlet is The method avoids Back-flow problem is Requires carefuldesign to minimize the IJ01, IJ03, IJ05, IJ06 located behind the problemof inlet eliminated negative pressure behind the paddle IJ07, IJ10,IJ11, IJ14 the ink-pushing back-flow by arrang- IJ16, IJ22, IJ23, IJ25surface ing the ink-pushing IJ28, IJ31, IJ32, IJ33 surface of the IJ34,IJ35, IJ36, IJ39 actuator between the IJ40, IJ41 inlet and the nozzle.Part of the The actuator and a Significant reductions in back- Smallincrease in fabrication complexity IJ07, IJ20, IJ26, IJ38 actuator moveswall of the ink flow can be achieved to shut off chamber are arrangedCompact designs possible the inlet so that the motion of the actuatorcloses off the inlet. Nozzle actuator In some configura- Ink back-flowproblem is None related to ink back-flow on Silverbrook, EP 0771 doesnot result tions of ink jet, eliminated actuation 658 A2 and related inink back-flow there is no expan- patent applications sion or movement ofValve-jet an actuator which may Tone-jet cause ink back-flow IJ08, IJ13,IJ15, IJ17 through the inlet. IJ18, IJ19, IJ21

[0173] NOZZLE CLEARING METHOD Nozzle Clearing method DescriptionAdvantages Disadvantages Examples Normal nozzle All of the nozzles areNo added complexity on the May not be sufficient to displace dried Mostink jet systems firing fired periodically, print head ink IJ01-IJ07,IJ09-IJ12 before the ink has a IJ14, IJ16, IJ20, IJ22 chance to dry.When IJ23-IJ34, IJ36-IJ45 not in use the nozzles are sealed (capped)against air. The nozzle firing is usually performed during a specialclear- ing cycle, after first moving the print head to a cleaningstation. Extra power to In systems which heat Can be highly effective ifthe Requires higher drive voltage for Silverbrook, EP 0771 ink heaterthe ink, but do not heater is adjacent to the clearing 658 A2 andrelated boil it under normal nozzle May require larger drive transistorspatent applications situations, nozzle clearing can be achieved by over-powering the heater and boiling ink at the nozzle. Rapid succession Theactuator is fired Does not require extra drive Effectiveness dependssubstantially May be used with: of actuator pulses in rapid succession.circuits on the print head upon the configuration of the inkjetIJ01-IJ07, IJ09-IJ11 In some configurations, Can be readily controlledand nozzle IJ14, IJ16, IJ20, IJ22 this may cause heat initiated bydigital logic IJ23-IJ25, IJ27-IJ34 build-up at the nozzle IJ36-IJ45which boils the ink, clearing the nozzle. In other situations, it maycause sufficient vibrations to dislodge clogged nozzles. Extra power toWhere an actuator is A simple solution where Not suitable where there isa hard limit May be used with: ink pushing not normally drivenapplicable to actuator movement IJ03, IJ09, IJ16, IJ20 actuator to thelimit of its IJ23, IJ24, IJ25, IJ27 motion, nozzle clearing IJ29, IJ30,IJ31, IJ32 may be assisted by IJ39, IJ40, IJ41, IJ42 providing anenhanced IJ43, IJ44, IJ45 drive signal to the actuator. Acoustic Anultrasonic wave is A high nozzle clearing High implementation cost ifsystem does IJ08, IJ13, IJ15, IJ17 resonance applied to the inkcapability can be achieved not already include an acoustic actuatorIJ18, IJ19, IJ21 chamber. This wave is May be implemented at very of anappropriate low cost in systems which amplitude and fre- already includeacoustic quency to cause actuators sufficient force at the nozzle toclear blockages. This is easiest to achieve if the ultrasonic wave is ata resonant frequency of the ink cavity. Nozzle clearing Amicrofabricated plate Can clear severely clogged Accurate mechanicalalignment is re- Silverbrook, EP 0771 plate is pushed against thenozzles quired 658 A2 and related nozzles. The plate has Moving partsare required patent applications a post for every nozzle. There is riskof damage to the nozzles The array of posts Accurate fabrication isrequired Ink pressure pulse The pressure of the May be effective whereother Requires pressure pump or other May be used with all IJ ink istemporarily methods cannot be used pressure actuator series ink jetsincreased so that ink Expensive streams from all of Wasteful of ink thenozzles. This may be used in con- junction with actuator energizing.Print head wiper A flexible ‘blade’ Effective for planar print headDifficult to use if print head surface is Many ink jet systems is wipedacross the surfaces non-planar or very fragile print head surface. Lowcost Requires mechanical parts The blade is usually Blade can wear outin high volume print fabricated from a systems flexible polymer, e.g.rubber or synthetic elastomer. Separate ink A separate heater is Can beeffective where other Fabrication complexity Can be used with manyboiling heater provided at the nozzle clearing methods IJ series inkjets nozzle although the cannot be used normal drop e-ection Can beimplemented at no mechanism does not additional cost in some inkjetrequire it. The configurations heaters do not require individual drivecircuits, as many nozzles can be cleared simultaneously, and no imagingis required.

[0174] NOZZLE PLATE CONSTRUCTION Nozzle plate construction DescriptionAdvantages Disadvantages Examples Electroformed A nozzle plate isFabrication simplicity High temperatures and pressures are HewlettPackard nickel separately fabricated required to bond nozzle plateThermal Inkjet from electroformed Minimum thickness constraints nickel,and bonded Differential thermal expansion to the print head chip. Laserablated or Individual nozzle holes No masks required Each hole must beindividually formed Canon Bubblejet drilled polymer are ablated by anCan be quite fast Special equipment required 1988 Sercel et al., intenseUV laser in a Some control over nozzle Slow where there are manythousands SPIE, Vol. 998 Excimer nozzle plate, which profile is possibleof nozzles per print head Beam Applications, is typically a polymerEquipment required is May produce thin burrs at exit holes pp. 76-83such as polyimide or relatively low cost 1993 Watanabe et al.,polysulphone U.S. Pat. No. 5,208,604 Silicon micro- A separate nozzleHigh accuracy is attainable Two part construction K. Bean, IEEE machinedplate is micromachined High cost Transactions on from single crystalRequires precision alignment Electron Devices, Vol. silicon, and bondedNozzles may be clogged by adhesive ED-25, No. 10, 1978, to the printhead pp 1185-1195 wafer. Xerox 1990 Hawkins et al., U.S. Pat. No.4,899,181 Glass Fine glass capillaries No expensive equipment Very smallnozzle sizes are difficult to 1970 Zoltan U.S. capillaries are drawnfrom glass required form Pat. No. 3,683,212 tubing. This method Simpleto make single nozzles Not suited for mass production has been used formaking individual nozzles, but is difficult to use for bulkmanufacturing of print heads with thousands of nozzles. Monolithic, Thenozzle plate is High accuracy (<1 μm) Requires sacrificial layer underthe Silverbrook, EP 0771 surface micro- deposited as a layer Monolithicnozzle plate to form the nozzle chamber 658 A2 and related machinedusing using standard VLSI Low cost Surface may be fragile to the touchpatent applications VLSI litho- deposition techniques. Existingprocesses can be IJ01, IJ02, IJ04, IJ11 graphic Nozzles are etched inused IJ12, IJ17, IJ18, IJ20 processes the nozzle plate using IJ22, IJ24,IJ27, IJ28 VLSI lithography and IJ29, IJ30, IJ31, IJ32 etching. IJ33,IJ34, IJ36, IJ37 IJ38, IJ39, IJ40, IJ41 IJ42, IJ43, IJ44 Monolithic, Thenozzle plate is a High accuracy (<1 μm) Requires long etch times IJ03,IJ05, IJ06, IJ07 etched through buried etch stop in Monolithic Requiresa support wafer IJ08, IJ09, IJ10, IJ13 substrate the wafer. Nozzle Lowcost IJ14, IJ15, IJ16, IJ19 chambers are etched in No differentialexpansion IJ21, IJ23, IJ25, IJ26 the front of the wafer, and the waferis thinned from the back side. Nozzles are then etched in the etch stoplayer. No nozzle plate Various methods have No nozzles to become cloggedDifficult to control drop position accu- Ricoh 1995 Sekiya et al beentried to eliminate rately U.S. Pat. No. 5,412,413 the nozzles entirely,Crosstalk problems 1993 Hadimioglu et al to prevent nozzle EUP 550,192clogging. These include 1993 Elrod et al EUP thermal bubble mecha-572,220 nisms and acoustic lens mechanisms Trough Each drop ejector hasReduced manufacturing Drop firing direction is sensitive to IJ35 atrough through complexity wicking. which a paddle moves. MonolithicThere is no nozzle plate. Nozzle slit The elimination of No nozzles tobecome clogged Difficult to control drop position accu- 1989 Saito et alinstead of nozzle holes and rately U.S. Pat. No. individual replacementby a Crosstalk problems 4,799,068 nozzles slit encompassing manyactuator posi- tions reduces nozzle clogging, but in- creases crosstalkdue to ink surface waves

[0175] DROP EJECTION DIRECTION Ejection direction Description AdvantagesDisadvantages Examples Edge Ink flow is along the Simple constructionNozzles limited to edge Canon Bubblejet 1979 (‘edge shooter’) surface ofthe chip, No silicon etching required High resolution is difficult Endoet al GB patent and ink drops are Good heat sinking via sub- Fast colorprinting requires one print 2,007,162 ejected from the chip strate headper color Xerox heater-in-pit 1990 edge. Mechanically strong Hawkins etal U.S. Ease of chip handing Pat. No. 4,899,181 Tone-jet Surface Inkflow is along the No bulk silicon etching Maximum ink flow is severelyrestricted Hewlett-Packard TIJ (‘roof shooter’) surface of the chip,required 1982 Vaught et al and ink drops are Silicon can make aneffective U.S. Pat. No. ejected from the chip heat sink 4,490,728surface, normal to Mechanical strength IJ02, IJ11, IJ12, IJ20 the planeof the chip. IJ22 Through chip, Ink flow is through High ink flowRequires bulk silicon etching Silverbrook, EP 0771 forward the chip, andink Suitable for pagewidth print 658 A2 and related (‘up shooter’) dropsare ejected High nozzle packing density patent applications from thefront sur- therefore low manufacturing IJ04, IJ17, IJ18, IJ24 face ofthe chip. cost IJ27-IJ45 Through chip, Ink flow is through High ink flowRequires wafer thinning IJ01, IJ03, IJ05, IJ06 reverse the chip, and inkSuitable for pagewidth print Requires special handling during IJ07,IJ08, IJ09, IJ10 (‘down shooter’) drops are ejected High nozzle packingdensity manufacture IJ13, IJ14, IJ15, IJ16 from the rear surfacetherefore low manufacturing IJ19, IJ21, IJ23, IJ25 of the chip. costIJ26 Through actuator Ink flow is through Suitable for piezoelectricPagewidth print heads require several Epson Stylus the actuator, whichprint heads thousand connections to drive circuits Tektronix hot melt isnot fabricated as Cannot be manufactured in standard piezoelectric inkjets part of the same CMOS fabs substrate as the Complex assemblyrequired drive transistors.

[0176] INK TYPE Ink type Description Advantages Disadvantages ExamplesAqueous, dye Water based ink Environmentally friendly Slow drying Mostexisting inkjets which typically No odor Corrosive All IJ series inkjets contains: water, Bleeds on paper Silverbrook, EP 0771 dye,surfactant, May strikethrough 658 A2 and related humectant, and Cocklespaper patent applications biocide. Modern ink dyes have high water-fastness, light fastness Aqueous, pigment Water based inkEnvironmentally friendly Slow drying IJ02, IJ04, IJ21, IJ26 whichtypically No odor Corrosive IJ27, IJ30 contains: water, Reduced bleedPigment may clog nozzles Silverbrook, EP 0771 pigment, surfactant,Reduced wicking Pigment may clog actuator mechanisms 658 A2 and relatedhumectant, and Reduced strikethrough Cockles paper patent applicationsbiocide. Piezoelectric ink-jets Pigments have an Thermal ink jets (withadvantage in reduced significant bleed, wicking restrictions) andstrikethrough. Methyl Ethyl MEK is a highly vola- Very fast dryingOdorous All IJ series ink jets Ketone (MEK) tile solvent used for Printson various substrates Flammable industrial printing such as metals andplastics on difficult surfaces such as aluminum cans. Alcohol Alcoholbased inks Fast drying Slight odor All IJ series ink jets (ethanol, 2-can be used where Operates at sub-freezing Flammable butanol, and theprinter must temperatures others) operate at tempera- Reduced papercockle tures below the Low cost freezing point of water. An example ofthis is in-camera consumer photographic printing. Phase change The inkis solid at No drying time - ink instantly High viscosity Tektronix hotmelt (hot melt) room temperature, and freezes on the print mediumPrinted ink typically has a ‘waxy’ feel piezoelectric ink jets is meltedin the Almost any print medium can Printed pages may ‘block’ 1989 NowakU.S. Pat. print head before jet- be used Ink temperature may be abovethe curie No. 4,820,346 ting. Hot melt inks No paper cockle occurs pointof permanent magnets All IJ series ink jets are usually wax based, Nowicking occurs Ink heaters consume power with a melting point No bleedoccurs Long warm-up time around 80° C. After No strikethrough occursjetting the ink freezes almost instantly upon contacting the printmedium or a transfer roller. Oil Oil based inks are High solubilitymedium for High viscosity: this is a significant All IJ series ink jetsextensively used in some dyes limitation for use in inkjets, whichoffset printing. They Does not cockle paper usually require a lowviscosity. Some have advantages in Does not wick through paper shortchain and multi-branched oils improved characteris- have a sufficientlylow viscosity. tics on paper (especi- Slow drying ally no wicking orcockle). Oil soluble dies and pigments are required. Microemulsion Amicroemulsion is a Stops ink bleed Viscosity higher than water All IJseries ink jets stable, self forming High dye solubility Cost isslightly higher than water based emulsion of oil, water, Water, oil, andamphiphilic ink and surfactant. The soluble dies can be used Highsurfactant concentration required characteristic drop Can stabilizepigment (around 5%) size is less than suspensions 100 nm, and is deter-mined by the preferred curvature of the surfactant.

[0177] Ink Jet Printing

[0178] A large number of new forms of ink jet printers have beendeveloped to facilitate alternative ink jet technologies for the imageprocessing and data distribution system. Various combinations of ink jetdevices can be included in printer devices incorporated as part of thepresent invention. Australian Provisional Patent Applications relatingto these ink jets which are specifically incorporated by cross referenceinclude: Australian Provisional Number Filing Date Title PO8066 15 Jul.1997 Image Creation Method and Apparatus (IJ01) PO8072 15 Jul. 1997Image Creation Method and Apparatus (IJ02) PO8040 15 Jul. 1997 ImageCreation Method and Apparatus (IJ03) PO8071 15 Jul. 1997 Image CreationMethod and Apparatus (IJ04) PO8047 15 Jul. 1997 Image Creation Methodand Apparatus (IJ05) PO8035 15 Jul. 1997 Image Creation Method andApparatus (IJ06) PO8044 15 Jul. 1997 Image Creation Method and Apparatus(IJ07) PO8063 15 Jul. 1997 Image Creation Method and Apparatus (IJ08)PO8057 15 Jul. 1997 Image Creation Method and Apparatus (IJ09) PO8056 15Jul. 1997 Image Creation Method and Apparatus (IJ10) PO8069 15 Jul. 1997Image Creation Method and Apparatus (IJ11) PO8049 15 Jul. 1997 ImageCreation Method and Apparatus (IJ12) PO8036 15 Jul. 1997 Image CreationMethod and Apparatus (IJ13) PO8048 15 Jul. 1997 Image Creation Methodand Apparatus (IJ14) PO8070 15 Jul. 1997 Image Creation Method andApparatus (IJ15) PO8067 15 Jul. 1997 Image Creation Method and Apparatus(IJ16) PO8001 15 Jul. 1997 Image Creation Method and Apparatus (IJ17)PO8038 15 Jul. 1997 Image Creation Method and Apparatus (IJ18) PO8033 15Jul. 1997 Image Creation Method and Apparatus (IJ19) PO8002 15 Jul. 1997Image Creation Method and Apparatus (IJ20) PO8068 15 Jul. 1997 ImageCreation Method and Apparatus (IJ21) PO8062 15 Jul. 1997 Image CreationMethod and Apparatus (IJ22) PO8034 15 Jul. 1997 Image Creation Methodand Apparatus (IJ23) PO8039 15 Jul. 1997 Image Creation Method andApparatus (IJ24) PO8041 15 Jul. 1997 Image Creation Method and Apparatus(IJ25) PO8004 15 Jul. 1997 Image Creation Method and Apparatus (IJ26)PO8037 15 Jul. 1997 Image Creation Method and Apparatus (IJ27) PO8043 15Jul. 1997 Image Creation Method and Apparatus (IJ28) PO8042 15 Jul. 1997Image Creation Method and Apparatus (IJ29) PO8064 15 Jul. 1997 ImageCreation Method and Apparatus (IJ30) PO9389 23 Sep. 1997 Image CreationMethod and Apparatus (IJ31) PO9391 23 Sep. 1997 Image Creation Methodand Apparatus (IJ32) PP0888 12 Dec. 1997 Image Creation Method andApparatus (IJ33) PP0891 12 Dec. 1997 Image Creation Method and Apparatus(IJ34) PP0890 12 Dec. 1997 Image Creation Method and Apparatus (IJ35)PP0873 12 Dec. 1997 Image Creation Method and Apparatus (IJ36) PP0993 12Dec. 1997 Image Creation Method and Apparatus (IJ37) PP0890 12 Dec. 1997Image Creation Method and Apparatus (IJ38) PP1398 19 Jan. 1998 An ImageCreation Method and Apparatus (IJ39) PP2592 25 Mar. 1998 An ImageCreation Method and Apparatus (IJ40) PP2593 25 Mar. 1998 Image CreationMethod and Apparatus (IJ41) PP3991 9 Jun. 1998 Image Creation Method andApparatus (IJ42) PP3987 9 Jun. 1998 Image Creation Method and Apparatus(IJ43) PP3985 9 Jun. 1998 Image Creation Method and Apparatus (IJ44)PP3983 9 Jun. 1998 Image Creation Method and Apparatus (IJ45)

[0179] Ink Jet Manufacturing

[0180] Further, the present application may utilize advancedsemiconductor fabrication techniques in the construction of large arraysof ink jet printers. Suitable manufacturing techniques are described inthe following Australian provisional patent specifications incorporatedhere by cross-reference: Australian Provisional Number Filing Date TitlePO7935 15 Jul. 1997 A Method of Manufacture of an Image CreationApparatus (IJM01) PO7936 15 Jul. 1997 A Method of Manufacture of anImage Creation Apparatus (IJM02) PO7937 15 Jul. 1997 A Method ofManufacture of an Image Creation Apparatus (IJM03) PO8061 15 Jul. 1997 AMethod of Manufacture of an Image Creation Apparatus (IJM04) PO8054 15Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM05)PO8065 15 Jul. 1997 A Method of Manufacture of an Image CreationApparatus (IJM06) PO8055 15 Jul. 1997 A Method of Manufacture of anImage Creation Apparatus (IJM07) PO8053 15 Jul. 1997 A Method ofManufacture of an Image Creation Apparatus (IJM08) PO8078 15 Jul. 1997 AMethod of Manufacture of an Image Creation Apparatus (IJM09) PO7933 15Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM10)PO7950 15 Jul. 1997 A Method of Manufacture of an Image CreationApparatus (IJM11) PO7949 15 Jul. 1997 A Method of Manufacture of anImage Creation Apparatus (IJM12) PO8060 15 Jul. 1997 A Method ofManufacture of an Image Creation Apparatus (IJM13) PO8059 15 Jul. 1997 AMethod of Manufacture of an Image Creation Apparatus (IJM14) PO8073 15Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM15)PO8076 15 Jul. 1997 A Method of Manufacture of an Image CreationApparatus (IJM16) PO8075 15 Jul. 1997 A Method of Manufacture of anImage Creation Apparatus (IJM17) PO8079 15 Jul. 1997 A Method ofManufacture of an Image Creation Apparatus (IJM18) PO8050 15 Jul. 1997 AMethod of Manufacture of an Image Creation Apparatus (IJM19) PO8052 15Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM20)PO7948 15 Jul. 1997 A Method of Manufacture of an Image CreationApparatus (IJM21) PO7951 15 Jul. 1997 A Method of Manufacture of anImage Creation Apparatus (IJM22) PO8074 15 Jul. 1997 A Method ofManufacture of an Image Creation Apparatus (IJM23) PO7941 15 Jul. 1997 AMethod of Manufacture of an Image Creation Apparatus (IJM24) PO8077 15Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM25)PO8058 15 Jul. 1997 A Method of Manufacture of an Image CreationApparatus (IJM26) PO8051 15 Jul. 1997 A Method of Manufacture of anImage Creation Apparatus (IJM27) PO8045 15 Jul. 1997 A Method ofManufacture of an Image Creation Apparatus (IJM28) PO7952 15 Jul. 1997 AMethod of Manufacture of an Image Creation Apparatus (IJM29) PO8046 15Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM30)PO8503 11 Aug. 1997 A Method of Manufacture of an Image CreationApparatus (IJM30a) PO9390 23 Sep. 1997 A Method of Manufacture of anImage Creation Apparatus (IJM31) PO9392 23 Sep. 1997 A Method ofManufacture of an Image Creation Apparatus (IJM32) PP0889 12 Dec. 1997 AMethod of Manufacture of an Image Creation Apparatus (IJM35) PP0887 12Dec. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM36)PP0882 12 Dec. 1997 A Method of Manufacture of an Image CreationApparatus (IJM37) PP0874 12 Dec. 1997 A Method of Manufacture of anImage Creation Apparatus (IJM38) PP1396 19 Jan. 1998 A Method ofManufacture of an Image Creation Apparatus (IJM39) PP2591 25 Mar. 1998 AMethod of Manufacture of an Image Creation Apparatus (IJM41) PP3989 9Jun. 1998 A Method of Manufacture of an Image Creation Apparatus (IJM40)PP3990 9 Jun. 1998 A Method of Manufacture of an Image CreationApparatus (IJM42) PP3986 9 Jun. 1998 A Method of Manufacture of an ImageCreation Apparatus (IJM43) PP3984 9 Jun. 1998 A Method of Manufacture ofan Image Creation Apparatus (IJM44) PP3982 9 Jun. 1998 A Method ofManufacture of an Image Creation Apparatus (IJM45)

[0181] Fluid Supply

[0182] Further, the present application may utilize an ink deliverysystem to the ink jet head. Delivery systems relating to the supply ofink to a series of ink jet nozzles are described in the followingAustralian provisional patent specifications, the disclosure of whichare hereby incorporated by cross-reference: Australian ProvisionalNumber Filing Date Title PO8003 15 Jul. 1997 Supply Method and Apparatus(F1) PO8005 15 Jul. 1997 Supply Method and Apparatus (F2) PO9404 23 Sep.1997 A Device and Method (F3)

[0183] MEMS Technology

[0184] Further, the present application may utilize advancedsemiconductor microelectromechanical techniques in the construction oflarge arrays of ink jet printers. Suitable microelectromechanicaltechniques are described in the following Australian provisional patentspecifications incorporated here by cross-reference: AustralianProvisional Number Filing Date Title PO7943 15 Jul. 1997 A device(MEMS01) PO8006 15 Jul. 1997 A device (MEMS02) PO8007 15 Jul. 1997 Adevice (MEMS03) PO8008 15 Jul. 1997 A device (MEMS04) PO8010 15 Jul.1997 A device (MEMS05) PO8011 15 Jul. 1997 A device (MEMS06) PO7947 15Jul. 1997 A device (MEMS07) PO7945 15 Jul. 1997 A device (MEMS08) PO794415 Jul. 1997 A device (MEMS09) PO7946 15 Jul. 1997 A device (MEMS10)PO9393 23 Sep. 1997 A Device and Method (MEMS11) PP0875 12 Dec. 1997 Adevice (MEMS12) PP0894 12 Dec. 1997 A Device and Method (MEMS13)

[0185] IR Technologies

[0186] Further, the present application may include the utilization of adisposable camera system such as those described in the followingAustralian provisional patent specifications incorporated here bycross-reference: Australian Provisional Number Filing Date Title PP089512 Dec. 1997 An Image Creation Method and Apparatus (IR01) PP0870 12Dec. 1997 A Device and Method (IR02) PP0869 12 Dec. 1997 A Device andMethod (IR04) PP0887 12 Dec. 1997 Image Creation Method and Apparatus(IR05) PP0885 12 Dec. 1997 An Image Production System (IR06) PP0884 12Dec. 1997 Image Creation Method and Apparatus (IR10) PP0886 12 Dec. 1997Image Creation Method and Apparatus (IR12) PP0871 12 Dec. 1997 A Deviceand Method (IR13) PP0876 12 Dec. 1997 An Image Processing Method andApparatus (IR14) PP0877 12 Dec. 1997 A Device and Method (IR16) PP087812 Dec. 1997 A Device and Method (IR17) PP0879 12 Dec. 1997 A Device andMethod (IR18) PP0883 12 Dec. 1997 A Device and Method (IR19) PP0880 12Dec. 1997 A Device and Method (IR20) PP0881 12 Dec. 1997 A Device andMethod (IR21)

[0187] DotCard Technologies

[0188] Further, the present application may include the utilization of adata distribution system such as that described in the followingAustralian provisional patent specifications incorporated here bycross-reference: Australian Provisional Number Filing Date Title PP237016 Mar. 1998 Data Processing Method and Apparatus (Dot01) PP2371 16 Mar.1998 Data Processing Method and Apparatus (Dot02)

[0189] Artcam Technologies

[0190] Further, the present application may include the utilization ofcamera and data processing techniques such as an Artcam type device asdescribed in the following Australian provisional patent specificationsincorporated here by cross-reference: Australian Provisional NumberFiling Date Title PO7991 15 Jul. 1997 Image Processing Method andApparatus (ART01) PO7988 15 Jul. 1997 Image Processing Method andApparatus (ART02) PO7993 15 Jul. 1997 Image Processing Method andApparatus (ART03) PO9395 23 Sep. 1997 Data Processing Method andApparatus (ART04) PO8017 15 Jul. 1997 Image Processing Method andApparatus (ART06) PO8014 15 Jul. 1997 Media Device (ART07) PO8025 15Jul. 1997 Image Processing Method and Apparatus (ART08) PO8032 15 Jul.1997 Image Processing Method and Apparatus (ART09) PO7999 15 Jul. 1997Image Processing Method and Apparatus (ART10) PO7998 15 Jul. 1997 ImageProcessing Method and Apparatus (ART11) PO8031 15 Jul. 1997 ImageProcessing Method and Apparatus (ART12) PO8030 15 Jul. 1997 Media Device(ART13) PO7997 15 Jul. 1997 Media Device (ART15) PO7979 15 Jul. 1997Media Device (ART16) PO8015 15 Jul. 1997 Media Device (ART17) PO7978 15Jul. 1997 Media Device (ART18) PO7982 15 Jul 1997 Data Processing Methodand Apparatus (ART 19) PO7989 15 Jul. 1997 Data Processing Method andApparatus (ART20) PO8019 15 Jul. 1997 Media Processing Method andApparatus (ART21) PO7980 15 Jul. 1997 Image Processing Method andApparatus (ART22) PO8018 15 Jul. 1997 Image Processing Method andApparatus (ART24) PO7938 15 Jul. 1997 Image Processing Method andApparatus (ART25) PO8016 15 Jul. 1997 Image Processing Method andApparatus (ART26) PO8024 15 Jul. 1997 Image Processing Method andApparatus (ART27) PO7940 15 Jul. 1997 Data Processing Method andApparatus (ART28) PO7939 15 Jul. 1997 Data Processing Method andApparatus (ART29) PO8501 11 Aug. 1997 Image Processing Method andApparatus (ART30) PO8500 11 Aug. 1997 Image Processing Method andApparatus (ART31) PO7987 15 Jul. 1997 Data Processing Method andApparatus (ART32) PO8022 15 Jul. 1997 Image Processing Method andApparatus (ART33) PO8497 11 Aug. 1997 Image Processing Method andApparatus (ART34) PO8020 15 Jul. 1997 Data Processing Method andApparatus (ART38) PO8023 15 Jul. 1997 Data Processing Method andApparatus (ART39) PO8504 11 Aug. 1997 Image Processing Method andApparatus (ART42) PO8000 15 Jul. 1997 Data Processing Method andApparatus (ART43) PO7977 15 Jul. 1997 Data Processing Method andApparatus (ART44) PO7934 15 Jul. 1997 Data Processing Method andApparatus (ART45) PO7990 15 Jul. 1997 Data Processing Method andApparatus (ART46) PO8499 11 Aug. 1997 Image Processing Method andApparatus (ART47) PO8502 11 Aug. 1997 Image Processing Method andApparatus (ART48) PO7981 15 Jul. 1997 Data Processing Method andApparatus (ART50) PO7986 15 Jul. 1997 Data Processing Method andApparatus (ART51) PO7983 15 Jul. 1997 Data Processing Method andApparatus (ART52) PO8026 15 Jul. 1997 Image Processing Method andApparatus (ART53) PO8027 15 Jul. 1997 Image Processing Method andApparatus (ART54) PO8028 15 Jul. 1997 Image Processing Method andApparatus (ART56) PO9394 23 Sep. 1997 Image Processing Method andApparatus (ART57) PO9396 23 Sep. 1997 Data Processing Method andApparatus (ART58) PO9397 23 Sep. 1997 Data Processing Method andApparatus (ART59) PO9398 23 Sep. 1997 Data Processing Method andApparatus (ART60) PO9399 23 Sep. 1997 Data Processing Method andApparatus (ART61) PO9400 23 Sep. 1997 Data Processing Method andApparatus (ART62) PO9401 23 Sep. 1997 Data Processing Method andApparatus (ART63) PO9402 23 Sep. 1997 Data Processing Method andApparatus (ART64) PO9403 23 Sep. 1997 Data Processing Method andApparatus (ART65) PO9405 23 Sep. 1997 Data Processing Method andApparatus (ART66) PP0959 16 Dec. 1997 A Data Processing Method andApparatus (ART68) PP1397 19 Jan. 1998 A Media Device (ART69)

We claim:
 1. a digital camera comprising: a jacket; a viewfinder locatedwithin said jacket for selecting an image; an image sensor devicelocated within said jacket for sensing said image; a processing meanslocated within said jacket for processing said sensed image; a pagewidthprint head located within said jacket for printing said sensed image; anink supply means located within said jacket for supplying ink to theprint head; a supply of print media on to which said image is printed,the supply of print media being pre-marked with tokens designating thatpostage has been paid so that each image printed out on the print mediahas one such token associated with it, the tokens being pre-printed atregularly spaced intervals on one surface of the print media.
 2. Adigital camera according to claim 1 wherein each token has an addresszone and a blank zone for writing associated with it on the one surfaceto provide a postcard effect.
 3. The camera of claim 1 in which thesupply of print media is in the form of a roll, the tokens beingpre-printed at regularly spaced intervals on one surface of the printmedia.
 4. The camera of claim 1 in which each image is printed on anopposed surface of the printed media.
 5. the camera of claim 1 in whichthe token is in a currency of a country in which the camera is bought,with a notice to that effect being carried on an exterior of the camera.